Abstract:
This invention provides novel arylindenopyridines of the formula:  
                         
and pharmaceutical compositions comprising same, useful for treating disorders ameliorated by antagonizing Adensine A2a receptors or reducing PDE activity in appropriate cells. This invention also provides therapeutic and prophylactic methods using the instant pharmaceutical compositions.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a divisional of co-pending application Ser. No. 11/042,281, filed on Jan. 24, 2005, which is a divisional of application Ser. No. 10/259,139, filed on Sep. 9, 2002, which is a continuation-in-part of co-pending application Ser. No. 10/123,389, filed on Apr. 16, 2002, which claims the benefit of provisional application Ser. No. 60/284,465 filed on Apr. 18, 2001, which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to novel arylindenopyridines and their therapeutic and prophylactic uses. Disorders treated and/or prevented using these compounds include neurodegenerative and movement disorders ameliorated by antagonizing Adenosine A2a receptors and inflammatory and AIDS-related disorders ameliorated by inhibiting phosphodiesterace activity.  
       BACKGROUND OF THE INVENTION  
       [0000]     Adenosine A2a Receptors  
         [0003]     Adenosine is a purine nucleotide produced by all metabolically active cells within the body. Adenosine exerts its effects via four subtypes of cell-surface receptors (A1, A2a, A2b and A3), which belong to the G protein coupled receptor superfamily (Stiles, G. L. Journal of Biological Chemistry, 1992, 267, 6451). A1 and A3 couple to inhibitory G protein, while A2a and A2b couple to stimulatory G protein. A2a receptors are mainly found in the brain, both in neurons and glial cells (highest level in the striatum and nucleus accumbens, moderate to high level in olfactory tubercle, hypothalamus, and hippocampus etc. regions) (Rosin, D. L.; Robeva, A.; Woodard, R. L.; Guyenet, P. G.; Linden, J. Journal of Comparative Neurology, 1998, 401, 163).  
         [0004]     In peripheral tissues, A2a receptors are found in platelets, neutrophils, vascular smooth muscle and endothelium (Gessi, S.; Varani, K.; Merighi, S.; Ongini, E.; Borea, P. A. British Journal of Pharmacology, 2000, 129, 2). The striatum is the main brain region for the regulation of motor activity, particularly through its innervation from dopaminergic neurons originating in the substantia nigra. The striatum is the major target of the dopaminergic neuron degeneration in patients with Parkinson&#39;s Disease (PD). Within the striatum, A2a receptors are co-localized with dopamine D2 receptors, suggesting an important site of for the integration of adenosine and dopamine signaling in the brain (Fink, J. S.; Weaver, D. R.; Rivkees, S. A.; Peterfreund, R. A.; Pollack, A. E.; Adler, E. M.; Reppert, S. M. Brain Research Molecular Brain Research, 1992, 14,186).  
         [0005]     Neurochemical studies have shown that activation of A2a receptors reduces the binding affinity of D2 agonist to their receptors. This D2R and A2aR receptor-receptor interaction has been demonstrated in striatal membrane preparations of rats (Ferre, S.; von Euler, G.; Johansson, B.; Fredholm, B. B.; Fuxe, K. Proceedings of the National Academy of Sciences of the United States of America, 1991, 88, 7238) as well as in fibroblast cell lines after transfected with A2aR and D2R cDNAs (Salim, H.; Ferre, S.; Dalal, A.; Peterfreund, R. A.; Fuxe, K.; Vincent, J. D.; Lledo, P. M. Journal of Neurochemistry, 2000, 74, 432). In vivo, pharmacological blockade of A2a receptors using A2a antagonist leads to beneficial effects in dopaminergic neurotoxin MPTP(1-methyl-4-pheny-l,2,3,6-tetrahydropyridine)-induced PD in various species, including mice, rats, and monkeys (Ikeda, K.; Kurokawa, M.; Aoyama, S.; Kuwana, Y. Journal of Neurochemistry, 2002, 80, 262). Furthermore, A2a knockout mice with genetic blockade of A2a function have been found to be less sensitive to motor impairment and neurochemical changes when they were exposed to neurotoxin MPTP (Chen, J. F.; Xu, K.; Petzer, J. P.; Staal, R.; Xu, Y. H.; Beilstein, M.; Sonsalla, P. K.; Castagnoli, K.; Castagnoli, N., Jr.; Schwarzschild, M. A. Journal of Neuroscience, 2001, 21, RC143).  
         [0006]     In humans, the adenosine receptor antagonist theophylline has been found to produce beneficial effects in PD patients (Mally, J.; Stone, T. W. Journal of the Neurological Sciences, 1995, 132, 129). Consistently, recent epidemiological study has shown that high caffeine consumption makes people less likely to develop PD (Ascherio, A.; Zhang, S. M.; Hernan, M. A.; Kawachi, I.; Colditz, G. A.; Speizer, F. E.; Willett, W. C. Annals of Neurology, 2001, 50, 56). In summary, adenosine A2a receptor blockers may provide a new class of antiparkinsonian agents (Impagnatiello, F.; Bastia, E.; Ongini, E.; Monopoli, A. Emerging Therapeutic Targets, 2000, 4, 635).  
         [0000]     Phosphodiesterase Inhibitors  
         [0007]     There are eleven known families of phosphodiesterases (PDE) widely distributed in many cell types and tissues. In their nomenclature, the number indicating the family is followed by a capital letter that indicates a distinct gene. A PDE inhibitor increases the concentration of cAMP in tissue cells, and hence, is useful in the prophylaxis or treatment of various diseases caused by the decrease in cAMP level which is induced by the abnormal metabolism of cAMP. These diseases include conditions such as hypersensitivity, allergy, arthritis, asthma, bee sting, animal bite, bronchospasm, dysmenorrhea, esophageal spasm, glaucoma, premature labor, a urinary tract disorder, inflammatory bowel disease, stroke, erectile dysfunction, HIV/AIDS, cardiovascular disease, gastrointestinal motility disorder, and psoriasis.  
         [0008]     Among known phosphodiesterases today, PDE1 family are activated by calcium-calmodulin; its members include PDE1A and PDE1B, which preferentially hydrolyze cGMP, and PDE1C which exhibits a high affinity for both cAMP and cGMP. PDE2 family is characterized as being specifically stimulated by cGMP. PDE2A is specifically inhibited by erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA). Enzymes in the PDE3 family (e.g. PDE3A, PDE3B) are specifically inhibited by cGMP. PDE4 (e.g. PDE4A, PDE4B, PDE4C, PDE4D) is a cAMP specific PDE present in T-cells, which is involved in inflammatory responses. A PDE3 and/or PDE4 inhibitor would be predicted to have utility in the following disorders: autoimmune disorders (e.g. arthritis), inflammatory bowel disease, bronchial disorders (e.g. asthma), HIV/AIDS, and psoriasis. A PDE5 (e.g. PDE5A) inhibitor would be useful for the treatment of the following disorders: cardiovascular disease and erectile dysfunction. The photoreceptor PDE6 (e.g. PDE6A, PDE6B, PDE6C) enzymes specifically hydrolyze cGMP. PDE8 family exhibits high affinity for hydrolysis of both cAMP and cGMP but relatively low sensitivity to enzyme inhibitors specific for other PDE families.  
         [0009]     Phosphodiesterase 7 (PDE7A, PDE7B) is a cyclic nucleotide phosphodiesterase that is specific for cyclic adenosine monophosphate (cAMP). PDE7 catalyzes the conversion of cAMP to adenosine monophosphate (AMP) by hydrolyzing the 3′-phosphodiester bond of cAMP. By regulating this conversion, PDE7 allows for non-uniform intracellular distribution of cAMP and thus controls the activation of distinct kinase signalling pathways. PDE7A is primarily expressed in T-cells, and it has been shown that induction of PDE7A is required for T-cell activation (Li, L.; Yee, C.; Beavo, J. A.  Science  1999, 283, 848). Since PDE7A activation is necessary for T-cell activation, small molecule inhibitors of PDE7 would be useful as immunosuppressants. An inhibitor of PDE7A would be predicted to have immunosuppressive effects with utility in therapeutic areas such as organ transplantation, autoimmune disorders (e.g. arthritis), HIV/AIDS, inflammatory bowel disease, asthma, allergies and psoriasis.  
         [0010]     Few potent inhibitors of PDE7 have been reported. Most inhibitors of other phosphodiesterases have IC 50 &#39;s for PDE7 in the 100 μM range. Recently, Martinez, et al. ( J. Med. Chem.  2000, 43, 683) reported a series of PDE7 inhibitors, among which the two best compounds have PDE7 IC 50 &#39;s of 8 and 13 μM. However, these compounds were only 2-3 times selective for PDE7 over PDE4 and PDE3.  
         [0011]     Finally, the following compounds have been disclosed, and some of them are reported to show antimicrobial activity against strains such as  Plasmodium falciparum, Candida albicans  and  Staphylococcus aureus  (Gorlitzer, K.; Herbig, S.; Walter, R. D.  Pharmazie  1997, 504):  
                         
 
       SUMMARY OF THE INVENTION  
       [0012]     This invention provides a compound having the structure of Formula I  
                         
 
 or a pharmaceutically acceptable salt thereof, wherein 
        (a) R 1  is selected from the group consisting of: 
            (i) —COR 5 , wherein R 5  is selected from H, optionally substituted C 1-8  straight or branched chain alkyl, optionally substituted aryl and optionally substituted arylalkyl; 
                wherein the substituents on the alkyl, aryl and arylalkyl group are selected from C 1-8  alkoxy, phenylacetyloxy, hydroxy, halogen, p-tosyloxy, mesyloxy, amino, cyano, carboalkoxy, or NR 20 R 21  wherein R 20  and R 21  are independently selected from the group consisting of hydrogen, C 1-8  straight or branched chain alkyl, C 3-7  cycloalkyl, benzyl, aryl, or heteroaryl or NR 20 R 21  taken together form a heterocycle or heteroaryl;    
                (ii) COOR 6 , wherein R 6  is selected from H, optionally substituted C 1-8  straight or branched chain alkyl, optionally substituted aryl and optionally substituted arylalkyl; 
                wherein the substituents on the alkyl, aryl and arylalkyl group are selected from C 1-8  alkoxy, phenylacetyloxy, hydroxy, halogen, p-tosyloxy, mesyloxy, amino, cyano, carboalkoxy, or NR 20 R 21  wherein R 20  and R 21  are independently selected from the group consisting of hydrogen, C 1-8  straight or branched chain alkyl, C 3-7  cycloalkyl, benzyl, aryl, or heteroaryl or NR 20 R 21  taken together form a heterocycle or heteroaryl;    
                (iii) cyano;     (iv) a lactone or lactam formed with R 4 ;     (v) —CONR 7 R 8  wherein R 7  and R 8  are independently selected from H, C 1-8  straight or branched chain alkyl, C 3-7  cycloalkyl, trifluoromethyl, hydroxy, alkoxy, acyl, alkylcarbonyl, carboxyl, arylalkyl, aryl, heteroaryl and heterocyclyl; 
                wherein the alkyl, cycloalkyl, alkoxy, acyl, alkylcarbonyl, carboxyl, arylalkyl, aryl, heteroaryl and heterocyclyl groups may be substituted with carboxyl, alkyl, aryl, substituted aryl, heterocyclyl, substituted heterocyclyl, heteroaryl, substituted heteroaryl, hydroxamic acid, sulfonamide, sulfonyl, hydroxy, thiol, alkoxy or arylalkyl,     or R 7  and R 8  taken together with the nitrogen to which they are attached form a heterocycle or heteroaryl group;    
                (vi) a carboxylic ester or carboxylic acid bioisostere including optionally substituted heteroaryl groups    
            (b) R 2  is selected from the group consisting of optionally substituted alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclyl and optionally substituted C 3-7  cycloalkyl;     (c) R 3  is from one to four groups independently selected from the group consisting of: 
            (i) hydrogen, halo, C 1-8  straight or branched chain alkyl, arylalkyl, C 3-7  cycloalkyl, C 1-8  alkoxy, cyano, C 1-4  carboalkoxy, trifluoromethyl, C 1-8  alkylsulfonyl, halogen, nitro, hydroxy, trifluoromethoxy, C 1-8  carboxylate, aryl, heteroaryl, and heterocyclyl;     (ii) —NR 10 R 11  wherein R 10  and R 11  are independently selected from H, C 1-8  straight or branched chain alkyl, arylalkyl, C 3-7  cycloalkyl, carboxyalkyl, aryl, heteroaryl, and heterocyclyl or R 10  and R 11  taken together with the nitrogen form a heteroaryl or heterocyclyl group;     (iii) —NR 12 COR 13  wherein R 12  is selected from hydrogen or alkyl and R 13  is selected from hydrogen, alkyl, substituted alkyl, C 1-3 alkoxyl, carboxyalkyl, R 30 R 31 N(CH 2 ) p —, R 30 R 31 NCO(CH 2 ) p —, aryl, arylalkyl, heteroaryl and heterocyclyl or R 12  and R 13  taken together with the carbonyl form a carbonyl containing heterocyclyl group, 
                wherein, R 30  and R 31  are independently selected from H, OH, alkyl, and alkoxy, and p is an integer from 1-6,     wherein the alkyl group may be substituted with carboxyl, alkyl, aryl, substituted aryl, heterocyclyl, substituted heterocyclyl, heteroaryl, substituted heteroaryl, hydroxamic acid, sulfonamide, sulfonyl, hydroxy, thiol, alkoxy or arylalkyl;    
               
            (d) R 4  is selected from the group consisting of (i) hydrogen, (ii) C 1-3  straight or branched chain alkyl, (iii) benzyl and (iv) —NR 13 R 14 , 
            wherein R 13  and R 14  are independently selected from hydrogen and C 1-6  alkyl;     wherein the C 1-3 alkyl and benzyl groups are optionally substituted with one or more groups selected from C 3-7  cycloalkyl, C 1-8  alkoxy, cyano, C 1-4  carboalkoxy, trifluoromethyl, C 1-8  alkylsulfonyl, halogen, nitro, hydroxy, trifluoromethoxy, C 1-8  carboxylate, amino, NR 13 R 14 , aryl and heteroaryl; and    
            (e) X is selected from S and O;     with the proviso that when R 4  is isopropyl, then R 3  is not halogen.        
 
         [0036]     In an alternative embodiment, the invention is directed to compounds of Formula I wherein R 1 , R 3  and R 4  are as described above and R 2  is —NR 15 R 16  wherein R 15  and R 16  are independently selected from hydrogen, optionally substituted C 1-8  straight or branched chain alkyl, arylalkyl, C 3-7  cycloalkyl, aryl, heteroaryl, and heterocyclyl or R 15  and R 16  taken together with the nitrogen form a heteroaryl or heterocyclyl group; with the proviso that when R 2  is NHR 16 , R 1  is not —COOR 6  where R 6  is ethyl.  
         [0037]     This invention also provides a pharmaceutical composition comprising the instant compound and a pharmaceutically acceptable carrier.  
         [0038]     This invention further provides a method of treating a subject having a condition ameliorated by antagonizing Adenosine A2a receptors or by reducing PDE activity in appropriate cells, which comprises administering to the subject a therapeutically effective dose of the instant pharmaceutical composition.  
         [0039]     This invention further provides a method of preventing a disorder ameliorated by antagonizing Adenosine A2a receptors or by reducing PDE activity in appropriate cells in a subject, comprising administering to the subject a prophylactically effective dose of the compound of claim  1  either preceding or subsequent to an event anticipated to cause a disorder ameliorated by antagonizing Adenosine A2a receptors or reducing PDE activity in appropriate cells in the subject. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0040]     Compounds of Formula 1 are potent small molecule antagonists of the Adenosine A2a receptors that have demonstrated potency for the antagonism of Adenosine A2a, A1, and A3 receptors.  
         [0041]     Compounds of Formula I are also potent small molecule phosphodiesterase inhibitors that have demonstrated potency for inhibition of PDE7, PDE5, and PDE4. Some of the compounds of this invention are potent small molecule PDE7 inhibitors which have also demonstrated good selectivity against PDE5 and PDE4.  
         [0042]     Preferred embodiments for R 1  are COOR 6 , wherein R 6  is selected from H, optionally substituted C 1-8  straight or branched chain alkyl, optionally substituted aryl and optionally substituted arylalkyl. Preferably R 6  is H, or C 1-8  straight or branched chain alkyl which may be optionally substituted with a substituent selected from CN and hydroxy.  
         [0043]     Preferred embodiments for R 2  are optionally substituted heterocycle, optionally substituted aryl and optionally substituted heteroaryl. Preferred substituents are from one to three members selected from the group consisting of halogen, alkyl, alkoxy, alkoxyphenyl, halo, triflouromethyl, trifluoro or difluoromethoxy, amino, alkylamino, hydroxy, cyano, and nitro. Preferably, R 2  is optionally substituted furan, phenyl or napthyl or R 2  is  
                         
 
 optionally substituted with from one to three members selected from the group consisting of halogen, alkyl, hydroxy, cyano, and nitro. In another embodiment of the instant compound, R 2  is —NR 15 R 16 . 
 
         [0044]     Preferred substituants for R 3  include: 
        (i) hydrogen, halo, C 1-8  straight or branched chain alkyl, C 1-8  alkoxy, cyano, C 1-4  carboalkoxy, trifluoromethyl, C 1-8  alkylsulfonyl, halogen, nitro, and hydroxy;     (ii) —NR 10 R 11  wherein R 10  and R 11  are independently selected from H, C 1-8  straight or branched chain alkyl, arylC 1-8 alkyl, C 3-7  cycloalkyl, carboxyC 1-8 alkyl, aryl, heteroaryl, and heterocyclyl or R 10  and R 11  taken together with the nitrogen form a heteroaryl or heterocyclyl group;     (iii) —NR 12 COR 13  wherein R 12  is selected from hydrogen or alkyl and R 13  is selected from hydrogen, alkyl, substituted alkyl, C 1-3 alkoxyl, carboxyC 1-8 alkyl, aryl, arylalkyl, R 30 R 31 N(CH 2 ) p —, R 30 R 31 NCO(CH 2 ) p —, heteroaryl and heterocyclyl or R 12  and R 13  taken together with the carbonyl form a carbonyl containing heterocyclyl group, wherein, R 30  and R 31  are independently selected from H, OH, alkyl, and alkoxy, and p is an integer from 1-6.        
 
         [0048]     Particularly, R 3  is selected from the group consisting of  
                         
 
         [0049]     Preferred embodiments for R 4  include hydrogen, C 1-3  straight or branched chain alkyl, particularly methyl, amine and amino.  
         [0050]     In a further embodiment of the instant compound, R 1  is COOR 6  and R 2  is selected from the group consisting of substituted phenyl, and substituted naphthyl or R 2  is NR 15 R 16 .  
         [0051]     More particularly, R 1  is COOR 6  where R 6  is alkyl, R 2  is substituted phenyl or naphthyl or R 2  is NR 15 R 16 , and R 3  is selected from the group consisting of H, nitro, amino, NHAc, halo, hydroxy, alkoxy, or a moiety of the formulae:  
                         
 
 alkyl(CO)NH—, and R 4  is selected from hydrogen, C 1-3  straight or branched chain alkyl, particularly methyl, and amino. 
 
         [0052]     In a preferred embodiment, the compound is selected from the group of compounds shown in Table 1 hereinafter.  
         [0053]     More preferably, the compound is selected from the following compounds:  
                         
 
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 2-amino-4-(1,3-benzodioxol-5-yl)-5-oxo-, ethyl ester  
       [0054]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(6-bromo-1,3-benzodioxol-5-yl)-2-methyl-5-oxo-, ethyl ester  
       [0055]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 7-amino-4-(1,3-benzodioxol-5-yl)-2-methyl-5-oxo-, ethyl ester  
       [0056]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(6-bromo-1,3-benzodioxol-5-yl)-2-methyl-5-oxo-, methyl ester  
       [0057]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5-dimethylphenyl)-2-methyl-5-oxo-, methyl ester  
       [0058]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 8-(acetylamino)-4-(1,3-benzodioxol-5-yl)-2-methyl-5-oxo-, ethyl ester  
       [0059]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 2-methyl-4-(3-methylphenyl)-5-oxo-, methyl ester  
       [0060]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 7-amino-4-(3,5-dimethylphenyl)-2-methyl-5-oxo-, methyl ester  
       [0061]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 7-amino-2-methyl-4-(4-methyl-1-naphthalenyl)-5-oxo-, methyl ester  
       [0062]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5-dibromo-4-hydroxyphenyl)-2-methyl-8-nitro-5-oxo-, methyl ester  
       [0063]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 7,8-dichloro-4-(3,5-dibromo-4-hydroxyphenyl)-2-methyl-5-oxo-, methyl ester  
       [0064]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 7-bromo-4-(3,5-dibromo-4-hydroxyphenyl)-2-methyl-5-oxo-, methyl ester  
       [0065]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 8-bromo-4-(3,5-dibromo-4-hydroxyphenyl)-2-methyl-5-oxo-, methyl ester  
       [0066]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 8-[(3-carboxy-1-oxopropyl)amino]-4-(3,5-dimethylphenyl)-2-methyl-5-oxo-, methyl ester  
       [0067]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 8-[(3-carboxy-1-oxopropyl)amino]-2-methyl-4-(4-methyl-1-naphthalenyl)-5-oxo-, methyl ester  
       [0068]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5-dimethylphenyl)-8-[[4-(hydroxyamino)-1,4-dioxobutyl]amino]-2-methyl-5-oxo-, methyl ester  
       [0069]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5-dimethylphenyl)-8-[[[(2-hydroxyethyl)amino]acetyl]amino]-2-methyl-5-oxo-, methyl ester  
       [0070]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 8-[(4-carboxy-1-oxobutyl)amino]-4-(3,5-dimethylphenyl)-2-methyl-5-oxo-, methyl ester  
       [0071]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5-dimethylphenyl)-8-[[[(2-hydroxyethyl)methylamino]acetyl]amino]-2-methyl-5-oxo-, methyl ester  
       [0072]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5-dimethylphenyl)-2-methyl-8-[(4-morpholinylacetyl)amino]-5-oxo-, methyl ester  
       [0073]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5-dimethylphenyl)-2-methyl-5-oxo-8-[(1-piperazinylacetyl)amino]-, methyl ester  
       [0074]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-phenyl-2-amino-5-oxo-, ethyl ester  
       [0075]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(4-methylphenyl)-2-methyl-5-oxo-, methyl ester  
       [0076]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3-bromophenyl)-2-methyl-5-oxo-, methyl ester  
       [0077]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3-bromophenylamino)-2-methyl-5-oxo-, methyl ester  
       [0078]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-phenyl-2-amino-5-oxo-, methyl ester  
       [0079]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(2-furyl)-2-amino-5-oxo-, methyl ester  
       [0080]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3-furyl)-2-amino-5-oxo-, methyl ester  
       [0081]    
       
                 
         
             
             
         
       
     
       5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(2-furyl)-2-amino-5-oxo-, ethyl ester  
       [0082]     The instant compounds can be isolated and used as free bases. They can also be isolated and used as pharmaceutically acceptable salts. Examples of such salts include hydrobromic, hydroiodic, hydrochloric, perchloric, sulfuric, maleic, fumaric, malic, tartaric, citric, benzoic, mandelic, methanesulfonic, hydroethanesulfonic, benzenesulfonic, oxalic, palmoic, 2-naphthalenesulfonic, p-toluenesulfonic, cyclohexanesulfamic and saccharic.  
         [0083]     This invention also provides a pharmaceutical composition comprising the instant compound and a pharmaceutically acceptable carrier.  
         [0084]     Pharmaceutically acceptable carriers are well known to those skilled in the art and include, but are not limited to, from about 0.01 to about 0.1 M and preferably 0.05 M phosphate buffer or 0.8% saline. Such pharmaceutically acceptable carriers can be aqueous or non-aqueous solutions, suspensions and emulsions. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. Aqueous carriers include water, ethanol, alcoholic/aqueous solutions, glycerol, emulsions or suspensions, including saline and buffered media. Oral carriers can be elixirs, syrups, capsules, tablets and the like. The typical solid carrier is an inert substance such as lactose, starch, glucose, methyl-cellulose, magnesium stearate, dicalcium phosphate, mannitol and the like. Parenteral carriers include sodium chloride solution, Ringer&#39;s dextrose, dextrose and sodium chloride, lactated Ringer&#39;s and fixed oils. Intravenous carriers include fluid and nutrient replenishers, electrolyte replenishers such as those based on Ringer&#39;s dextrose and the like. Preservatives and other additives can also be present, such as, for example, antimicrobials, antioxidants, chelating agents, inert gases and the like. All carriers can be mixed as needed with disintegrants, diluents, granulating agents, lubricants, binders and the like using conventional techniques known in the art.  
         [0085]     This invention further provides a method of treating a subject having a condition ameliorated by antagonizing Adenosine A2a receptors or by reducing PDE activity in appropriate cells, which comprises administering to the subject a therapeutically effective dose of the instant pharmaceutical composition.  
         [0086]     In one embodiment, the disorder is a neurodegenerative or movement disorder. In another embodiment, the disorder is an inflammatory disorder. In still another embodiment, the disorder is an AIDS-related disorder. Examples of disorders treatable by the instant pharmaceutical composition include, without limitation, Parkinson&#39;s Disease, Huntington&#39;s Disease, Multiple System Atrophy, Corticobasal Degeneration, Alzheimer&#39;s Disease, Senile Dementia, organ transplantation, autoimmune disorders (e.g. arthritis), immune challenge such as a bee sting, inflammatory bowel disease, bronchial disorders (e.g. asthma), HIV/AIDS, cardiovascular disorder, erectile dysfunction, allergies, and psoriasis.  
         [0087]     In one preferred embodiment, the disorder is rheumatoid arthritis.  
         [0088]     In another preferred embodiment, the disorder is Parkinson&#39;s disease.  
         [0089]     As used herein, the term “subject” includes, without limitation, any animal or artificially modified animal having a disorder ameliorated by reducing PDE activity in appropriate cells. In a preferred embodiment, the subject is a human. In a more preferred embodiment, the subject is a human.  
         [0090]     As used herein, “appropriate cells” include, by way of example, cells which display PDE activity. Specific examples of appropriate cells include, without limitation, T-lymphocytes, muscle cells, neuro cells, adipose tissue cells, monocytes, macrophages, fibroblasts.  
         [0091]     Administering the instant pharmaceutical composition can be effected or performed using any of the various methods known to those skilled in the art. The instant compounds can be administered, for example, intravenously, intramuscularly, orally and subcutaneously. In the preferred embodiment, the instant pharmaceutical composition is administered orally. Additionally, administration can comprise giving the subject a plurality of dosages over a suitable period of time. Such administration regimens can be determined according to routine methods.  
         [0092]     As used herein, a “therapeutically effective dose” of a pharmaceutical composition is an amount sufficient to stop, reverse or reduce the progression of a disorder. A “prophylactically effective dose” of a pharmaceutical composition is an amount sufficient to prevent a disorder, i.e., eliminate, ameliorate and/or delay the disorder&#39;s onset. Methods are known in the art for determining therapeutically and prophylactically effective doses for the instant pharmaceutical composition. The effective dose for administering the pharmaceutical composition to a human, for example, can be determined mathematically from the results of animal studies.  
         [0093]     In one embodiment, the therapeutically and/or prophylactically effective dose is a dose sufficient to deliver from about 0.001 mg/kg of body weight to about 200 mg/kg of body weight of the instant pharmaceutical composition. In another embodiment, the therapeutically and/or prophylactically effective dose is a dose sufficient to deliver from about 0.05 mg/kg of body weight to about 50 mg/kg of body weight. More specifically, in one embodiment, oral doses range from about 0.05 mg/kg to about 100 mg/kg daily. In another embodiment, oral doses range from about 0.05 mg/kg to about 50 mg/kg daily, and in a further embodiment, from about 0.05 mg/kg to about 20 mg/kg daily in yet another embodiment, infusion doses range from about 1.0 μg/kg/min to about 10 mg/kg/min of inhibitor, admixed with a pharmaceutical carrier over a period ranging from about several minutes to about several days. In a further embodiment, for topical administration, the instant compound can be combined with a pharmaceutical carrier at a drug/carrier ratio of from about 0.001 to about 0.1.  
         [0094]     This invention still further provides a method of preventing an inflammatory response in a subject, comprising administering to the subject a prophylactically effective amount of the instant pharmaceutical composition either preceding or subsequent to an event anticipated to cause the inflammatory response in the subject. In the preferred embodiment, the event is an insect sting or an animal bite.  
       DEFINITIONS AND NOMENCLATURE  
       [0095]     Unless otherwise noted, under standard nomenclature used throughout this disclosure the terminal portion of the designated side chain is described first, followed by the adjacent functionality toward the point of attachment.  
         [0096]     As used herein, the following chemical terms shall have the meanings as set forth in the following paragraphs: “independently”, when in reference to chemical substituents, shall mean that when more than one substituent exists, the substituents may be the same or different;.  
         [0097]     “Alkyl” shall mean straight, cyclic and branched-chain alkyl. Unless otherwise stated, the alkyl group will contain 1-20 carbon atoms. Unless otherwise stated, the alkyl group may be optionally substituted with one or more groups such as halogen, OH, CN, mercapto, nitro, amino, C 1 -C 8 -alkyl, C 1 -C 8 -alkoxyl, C 1 -C 8 -alkylthio, C 1 -C 8 -alkyl-amino, di(C 1 -C 8 -alkyl)amino, (mono-, di-, tri-, and per-) halo-alkyl, formyl, carboxy, alkoxycarbonyl, C 1 -C 8 -alkyl-CO—O—, C 1 -C 8 -alkyl-CO—NH—, carboxamide, hydroxamic acid, sulfonamide, sulfonyl, thiol, aryl, aryl(c 1 -c 8 )alkyl, heterocyclyl, and heteroaryl.  
         [0098]     “Alkoxy” shall mean —O-alkyl and unless otherwise stated, it will have 1-8 carbon atoms.  
         [0099]     The term “bioisostere” is defined as “groups or molecules which have chemical and physical properties producing broadly similar biological properties.” (Burger&#39;s Medicinal Chemistry and Drug Discovery, M. E. Wolff, ed. Fifth Edition, Vol. 1, 1995, Pg. 785).  
         [0100]     “Halogen” shall mean fluorine, chlorine, bromine or iodine; “PH” or “Ph” shall mean phenyl; “Ac” shall mean acyl; “Bn” shall mean benzyl.  
         [0101]     The term “acyl” as used herein, whether used alone or as part of a substituent group, means an organic radical having 2 to 6 carbon atoms (branched or straight chain) derived from an organic acid by removal of the hydroxyl group. The term “Ac” as used herein, whether used alone or as part of a substituent group, means acetyl.  
         [0102]     “Aryl” or “Ar,” whether used alone or as part of a substituent group, is a carbocyclic aromatic radical including, but not limited to, phenyl, 1- or 2-naphthyl and the like. The carbocyclic aromatic radical may be substituted by independent replacement of 1 to 5 of the hydrogen atoms thereon with halogen, OH, CN, mercapto, nitro, amino, C 1 -C 8 -alkyl, C 1 -C 8 -alkoxyl, C 1 -C 8 -alkylthio, C 1 -C 8 -alkyl-amino, di(C 1 -C 8 -alkyl)amino, (mono-, di-, tri-, and per-) halo-alkyl, formyl, carboxy, alkoxycarbonyl, C 1 -C 8 -alkyl-CO—O—, C 1 -C 8 -alkyl-CO—NH—, or carboxamide. Illustrative aryl radicals include, for example, phenyl, naphthyl, biphenyl, fluorophenyl, difluorophenyl, benzyl, benzoyloxyphenyl, carboethoxyphenyl, acetylphenyl, ethoxyphenyl, phenoxyphenyl, hydroxyphenyl, carboxyphenyl, trifluoromethylphenyl, methoxyethylphenyl, acetamidophenyl, tolyl, xylyl, dimethylcarbamylphenyl and the like. “Ph” or “PH” denotes phenyl.  
         [0103]     Whether used alone or as part of a substituent group, “heteroaryl” refers to a cyclic, fully unsaturated radical having from five to ten ring atoms of which one ring atom is selected from S, O, and N; 0-2 ring atoms are additional heteroatoms independently selected from S, O, and N; and the remaining ring atoms are carbon. The radical may be joined to the rest of the molecule via any of the ring atoms. Exemplary heteroaryl groups include, for example, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyrroyl, pyrazolyl, imidazolyl, thiazolyl, oxazolyl, isoxazolyl, thiadiazolyl, triazolyl, triazinyl, oxadiazolyl, thienyl, furanyl, quinolinyl, isoquinolinyl, indolyl, isothiazolyl, 2-oxazepinyl, azepinyl, N-oxo-pyridyl, 1-dioxothienyl, benzothiazolyl, benzoxazolyl, benzothienyl, quinolinyl-N-oxide, benzimidazolyl, benzopyranyl, benzisothiazolyl, benzisoxazolyl, benzodiazinyl, benzofurazanyl, benzothiopyranyl, indazolyl, indolizinyl, benzofuryl, chromonyl, coumarinyl, cinnolinyl, quinoxalinyl, indazolyl, pyrrolopyridinyl, furopyridinyl (such as furo[2,3-c]pyridinyl, furo[3,2-b]pyridinyl, or furo[2,3-b]pyridinyl), imidazopyridinyl (such as imidazo[4,5-b]pyridinyl or imidazo[4,5-c]pyridinyl), naphthyridinyl, phthalazinyl, purinyl, pyridopyridyl, quinazolinyl, thienofuryl, thienopyridyl, thienothienyl, and furyl. The heteroaryl group may be substituted by independent replacement of 1 to 5 of the hydrogen atoms thereon with halogen, OH, CN, mercapto, nitro, amino, C 1 -C 8 -alkyl, C 1 -C 8 -alkoxyl, C 1 -C 8 -alkylthio, C 1 -C 8 -alkyl-amino, di(C 1 -C 8 -alkyl)amino, (mono-, di-, tri-, and per-) halo-alkyl, formyl, carboxy, alkoxycarbonyl, C 1 -C 8 -alkyl-CO—O—, C 1 -C 8 -alkyl-CO—NH—, or carboxamide. Heteroaryl may be substituted with a mono-oxo to give for example a 4-oxo-1H-quinoline.  
         [0104]     The terms “heterocycle,” “heterocyclic,” and “heterocyclo” refer to an optionally substituted, fully or partially saturated cyclic group which is, for example, a 4- to 7-membered monocyclic, 7- to 11-membered bicyclic, or 10- to 15-membered tricyclic ring system, which has at least one heteroatom in at least one carbon atom containing ring. Each ring of the heterocyclic group containing a heteroatom may have 1, 2, or 3 heteroatoms selected from nitrogen atoms, oxygen atoms, and sulfur atoms, where the nitrogen and sulfur heteroatoms may also optionally be oxidized. The nitrogen atoms may optionally be quaternized. The heterocyclic group may be attached at any heteroatom or carbon atom.  
         [0105]     Exemplary monocyclic heterocyclic groups include pyrrolidinyl; oxetanyl; pyrazolinyl; imidazolinyl; imidazolidinyl; oxazolyl; oxazolidinyl; isoxazolinyl; thiazolidinyl; isothiazolidinyl; tetrahydrofuryl; piperidinyl; piperazinyl; 2-oxopiperazinyl; 2-oxopiperidinyl; 2-oxopyrrolidinyl; 4-piperidonyl; tetrahydropyranyl; tetrahydrothiopyranyl; tetrahydrothiopyranyl sulfone; morpholinyl; thiomorpholinyl; thiomorpholinyl sulfoxide; thiomorpholinyl sulfone; 1,3-dioxolane; dioxanyl; thietanyl; thiiranyl; and the like. Exemplary bicyclic heterocyclic groups include quinuclidinyl; tetrahydroisoquinolinyl; dihydroisoindolyl; dihydroquinazolinyl (such as 3,4-dihydro-4-oxo-quinazolinyl); dihydrobenzofuryl; dihydrobenzothienyl; dihydrobenzothiopyranyl; dihydrobenzothiopyranyl sulfone; dihydrobenzopyranyl; indolinyl; isochromanyl; isoindolinyl; piperonyl; tetrahydroquinolinyl; and the like.  
         [0106]     Substituted aryl, substituted heteroaryl, and substituted heterocycle may also be substituted with a second substituted-aryl, a second substituted-heteroaryl, or a second substituted-heterocycle to give, for example, a 4-pyrazol-1-yl-phenyl or 4-pyridin-2-yl-phenyl.  
         [0107]     Designated numbers of carbon atoms (e.g., C 1-8 ) shall refer independently to the number of carbon atoms in an alkyl or cycloalkyl moiety or to the alkyl portion of a larger substituent in which alkyl appears as its prefix root.  
         [0108]     Unless specified otherwise, it is intended that the definition of any substituent or variable at a particular location in a molecule be independent of its definitions elsewhere in that molecule. It is understood that substituents and substitution patterns on the compounds of this invention can be selected by one of ordinary skill in the art to provide compounds that are chemically stable and that can be readily synthesized by techniques known in the art as well as those methods set forth herein.  
         [0109]     Where the compounds according to this invention have at least one stereogenic center, they may accordingly exist as enantiomers. Where the compounds possess two or more stereogenic centers, they may additionally exist as diastereomers. Furthermore, some of the crystalline forms for the compounds may exist as polymorphs and as such are intended to be included in the present invention. In addition, some of the compounds may form solvates with water (i.e., hydrates) or common organic solvents, and such solvates are also intended to be encompassed within the scope of this invention.  
         [0110]     Some of the compounds of the present invention may have trans and cis isomers. In addition, where the processes for the preparation of the compounds according to the invention give rise to mixture of stereoisomers, these isomers may be separated by conventional techniques such as preparative chromatography. The compounds may be prepared as a single stereoisomer or in racemic form as a mixture of some possible stereoisomers. The non-racemic forms may be obtained by either synthesis or resolution. The compounds may, for example, be resolved into their components enantiomers by standard techniques, such as the formation of diastereomeric pairs by salt formation. The compounds may also be resolved by covalent linkage to a chiral auxiliary, followed by chromatographic separation and/or crystallographic separation, and removal of the chiral auxiliary. Alternatively, the compounds may be resolved using chiral chromatography.  
         [0111]     This invention will be better understood by reference to the Experimental Details which follow, but those skilled in the art will readily appreciate that these are only illustrative of the invention as described more fully in the claims which follow thereafter. Additionally, throughout this application, various publications are cited. The disclosure of these publications is hereby incorporated by reference into this application to describe more fully the state of the art to which this invention pertains.  
         [0000]     Experimental Details  
         [0000]     I. General Synthetic Schemes  
         [0112]     Representative compounds of the present invention can be synthesized in accordance with the general synthetic methods described below and illustrated in the following general schemes. The products of some schemes can be used as intermediates to produce more than one of the instant compounds. The choice of intermediates to be used to produce subsequent compounds of the present invention is a matter of discretion that is well within the capabilities of those skilled in the art.  
                         
 
         [0113]     Procedures described in Scheme 1, wherein R 3a , R 3b , R 3c , and R 3d  are independently any R 3  group, and R 1 , R 2 , R 3 , and R 4  are as described above, can be used to prepare compounds of the invention wherein X is O.  
         [0114]     Benzylidenes 2 may be obtained by known methods (Bullington, J. L; Cameron, J. C.; Davis, J. E.; Dodd, J. H.; Harris, C. A.; Henry, J. R.; Pellegrino-Gensey, J. L.; Rupert, K. C.; Siekierka, J. J. Bioorg. Med. Chem. Lett. 1998, 8, 2489; Petrow, V.; Saper, J.; Sturgeon, B. J. Chem. Soc. 1949, 2134). Hantzsch reaction of the benzylidene compounds with enamines 3 can be performed in refluxing acetic acid (Petrow et al., supra). When the desired enamines are not available, alternate Hantzsch conditions may be utilized which involve adding ammonium acetate to the reaction. The resulting dihydropyridines 4 are oxidized with chromium trioxide to obtain the desired pyridines 1 (Petrow et al., supra). In cases where the substitution pattern on the fused aromatic ring (R 3 ) leads to a mixture of regioisomers, the products can be separated by column chromatography.  
         [0115]     In some cases, especially where R 2  is an alkyl group, another modification of the Hantzsch may be performed which uses three components (Bocker, R. H.; Buengerich, P.  J. Med. Chem.  1986, 29,1596). Where R 2  is an alkyl group it is also necessary to perform the oxidation with DDQ or MnO 2  instead of chromium (VI) oxide (Vanden Eynde, J. J.; Delfosse, F.; Mayence, A.; Van Haverbeke, Y.  Tetrahedron  1995, 51, 6511).  
                         
 
         [0116]     In order to obtain the corresponding carboxylic acids and amides, the cyanoethyl esters 5 are prepared as described above. The esters are converted to the carboxylic acids by treatment with sodium hydroxide in acetone and water (Ogawa, T.; Matsumoto, K.; Yokoo, C.; Hatayama, K.; Kitamura, K.  J. Chem. Soc., Perkin Trans.  1 1993, 525). The corresponding amides can then be obtained from the acids using standard means.  
                         
 
         [0117]     The procedure for making compounds where R 4  is NH 2  may be slightly modified. These compounds are prepared in one step from the benzylidenes 2 and alkyl amidinoacetate (Kobayashi, T.; Inoue, T.; Kita, Z.; Yoshiya, H.; Nishino, S.; Oizumi, K.; Kimura, T.  Chem. Pharm. Bull.  1995, 43, 788) as depicted in Scheme 4 wherein R is R 5  or R 6  as described above.  
                         
 
         [0118]     The dihydropyridine lactones 9 can be synthesized from benzylidenes 8 (Zimmer, H.; Hillstrom, W. W.; Schmidt, J. C.; Seemuth, P. D.; Vogeli, R.  J. Org. Chem.  1978, 43, 1541) and 1,3-indanedione, as shown in Scheme 5, and the corresponding pyridine is then obtained by oxidation with manganese dioxide.  
                         
 
         [0119]     Representative schemes to modify substituents on the fused aromatic ring are shown below. The amines 11 are obtained from the corresponding nitro compounds 10 by reduction with tin (II) chloride (Scheme 6). Reaction of the amines with acetyl chloride provide the amides 12.  
                         
 
         [0120]     In accordance with Scheme 7 wherein Y is O, and n is an integer from 1-3, an alkyl chain with a carboxylic acid at the terminal end can also be added to the amines 11. For example, reaction with either succinic anhydride (Omuaru, V. O. T.;  Indian J. Chem.,  Sect B. 1998, 37, 814) or β-propiolactone (Bradley, G.; Clark, J.; Kernick, W.  J. Chem. Soc., Perkin Trans.  1 1972, 2019) can provide the corresponding carboxylic acids 13. These carboxylic acids are then converted to the hydroxamic acids 14 by treatment with ethyl chloroformate and hydroxylamine (Reddy, A. S.; Kumar, M. S.; Reddy, G. R.  Tetrahedron Lett.  2000, 41, 6285).  
                         
 
         [0121]     The amines 11 can also be treated with glycolic acid to afford alcohols 15 (Jursic, B. S.; Zdravkovski, Z.  Synthetic Comm.  1993, 23, 2761) as shown in Scheme 8.  
                         
 
         [0122]     As shown in Scheme 9, the aminoindenopyridines 11 may also be treated with chloroacetylchloride followed by amines to provide the more elaborate amines 16 (Weissman, S. A.; Lewis, S.; Askin, D.; Volante, R. P.; Reider, P. J.  Tetrahedron Lett.  1998, 39, 7459). Where R 6  is a hydroxyethyl group, the compounds can be further converted to piperazinones 17.  
                         
 
         [0123]     The 4-aminoindenopyridines 19 can be synthesized from the 4-chloroindenopyridines 18 using a known procedure (Gorlitzer, K.; Herbig, S.; Walter, R. D.  Pharmazie  1997, 504) or via palladium catalyzed coupling (Scheme 10).  
                         
 
         [0124]     Cyanoesters 20 can be prepared by known methods (Lee, J.; Gauthier, D.; Rivero, R. A.  J. Org. Chem.  1999, 64, 3060). Reaction of 20 with enaminone 21 (Iida, H.; Yuasa, Y.; Kibayashi, C. J. Org. Chem. 1979, 44, 1074) in refluxing 1-propanol and triethylamine gave dihydropyridine 22, wherein R is R 5  or R 6  as described above, (Youssif, S.; EI-Bahaie, S.; Nabih, E.  J. Chem. Res.  ( S ) 1999, 112 and Bhuyan, P.; Borush, R. C.; Sandhu, J. S.  J. Org. Chem.  1990, 55, 568), which can then be oxidized and subsequently deprotected to give pyridine 23.  
                         
 
 II. Specific Compound Syntheses 
 
         [0125]     Specific compounds which are representative of this invention can be prepared as per the following examples. No attempt has been made to optimize the yields obtained in these reactions. Based on the following, however, one skilled in the art would know how to increase yields through routine variations in reaction times, temperatures, solvents and/or reagents.  
         [0126]     The products of certain syntheses can be used as intermediates to produce more than one of the instant compounds. In those cases, the choice of intermediates to be used to produce compounds of the present invention is a matter of discretion that is well within the capabilities of those skilled in the art.  
       EXAMPLE 1  
     Hantzsch Condensation to Form Dihydropyridine 4  
     (R 1 ═COOMe; R 2 =3,5-dimethylphenyl; R 3b,c ═Cl: R 3a,b ═H: R 4 =Me)  
       [0127]     To a refluxing solution of benzylidene 2 (0.500 g, 1.5 mmol) in acetic acid (10 mL) was added methyl-3-aminocrotonate (0.695 g, 6.0 mmol). The reaction was heated to reflux for 20 minutes, then water was added until a precipitate started to form. The reaction was cooled to room temperature. The mixture was filtered and washed with water to obtain 0.354 g (55%) of a red solid. MS m/z 450 (M + +23), 428 (M + +1).  
       EXAMPLE 2  
     Alternate Hantzsch Conditions to Form Dihydropyridine 4  
     (R 1 ═CO 2 Me; R 2 =2,4-dimethylphenyl; R 3 ═H; R 4 =Et)  
       [0128]     To a refluxing solution of benzylidene 2 (1.00 g, 3.82 mmol) in acetic acid (12 MI) was added methyl propionylacetate (1.98 g, 15.2 mmol) and ammonium acetate (1.17 g, 15.2 mmol). The reaction was heated for 20 min and then cooled to room temperature. No product precipitated from the solution, so the reaction was heated to reflux and then water was added until a solid began to precipitate. After cooling to room temperature, the mixture was filtered and the red solid washed with water to yield 1.29 g (90%) of product. MS m/z 396 (M + +23), 374 (M + +1).  
       EXAMPLE 3  
     Oxidation of Dihydropyridine 4 to Pyridine 1  
     (R 1 ═COOMe; R 2 =3,5-dimethylphenyl; R 3b,c ═Cl; R 3a,d ═H; R 4 =Me)  
       [0129]     To a refluxing solution of dihydropyridine 4 (0.250 g, 0.58 mmol) in acetic acid (10 mL) was added a solution of chromium (VI) oxide (0.584 g, 0.58 mmol) in 1 mL water. After 30 minutes at reflux, the reaction was diluted with water until a precipitate started to form. The mixture was cooled to room temperature and allowed to stand overnight. The mixture was filtered and washed with water to give 0.199 g (81%) of a yellow solid. MS m/z 448 (M + +23), 426 (M + +1).  
       EXAMPLE 4  
     Oxidation of Dihydropyridine 4 to Pyridine 1  
     (R 1 ═COOMe; R 2 =(4-methyl)-1-naphthyl; R 3b,c ═H, NO 2 /NO 2 , H; R=Me)  
       [0130]     To a refluxing suspension of regioisomeric dihydropyridines 4 (3.59 g, 8.16 mmol) in acetic acid (40 mL) was added a solution of chromium (VI) oxide (0.816 g, 8.16 mmol) in 3 mL water. After 20 minutes at reflux, the reaction was diluted with water until a precipitate started to form. The mixture was cooled to room temperature and allowed to stand overnight. The mixture was filtered and washed with water to yield the mixture of regioisomers as a yellow solid. The products were purified by column chromatography eluting with hexanes:ethyl acetate to yield 1.303 g (37%) of pyridine 1 (R 3b ═NO 2 ; R 3c ═H) and 0.765 g (21%) of its regioisomer (R 3b ═H: R 3c ═NO 2 ). MS m/z 461 (M + +23), 439 (M + +1).  
       EXAMPLE 5  
     Alternate Three Component Hantzsch Reaction to Form Dihydropyridine 4  
     (R 1 ═CO 2 Me; R 2 =cyclohexyl; R 3 ═H; R 4 =Me)  
       [0131]     Cyclohexane carboxaldehyde (2.0 g, 17.8 mmol), 1,3-indandione (2.6 g, 17.8 mmol), methylacetoacetate (2.0 g, 17.8 mmol), and ammonium hydroxide (1 mL) were refluxed in 8 mL of methanol for 1.5 hours. The temperature was lowered to approximately 50° C. and the reaction was stirred overnight. The reaction was cooled to room temperature, filtered and the solid washed with water. The residue was then dissolved in hot ethanol and filtered while hot. The filtrate was concentrated to yield 4.1 g (68%) of the product which was used without purification. MS m/z 336 (M − −1).  
       EXAMPLE 6  
     DDQ Oxidation of Dihydropyridine 4  
     (R 1 ═CO 2 Me; R 2 =cyclohexyl; R 3 ═H: R 4 =Me)  
       [0132]     To a solution of dihydropyridine 4 (2.50 g, 7.40 mmol) in 15 mL of dichloromethane was added 2,3-dichloro-3,6-dicyano-1,4-benzoquinone (1.70 g, 7.40 mmol). The reaction was stirred at room temperature for four hours. The mixture was filtered and the residue was washed with dichloromethane. After the filtrate was concentrated, the residue was purified by column chromatography eluting with ethyl acetate: hexanes to yield 0.565 g (23%) of a yellow solid. MS m/z 358 (M + +23), 336 (M + +1).  
       EXAMPLE 7  
     MnO 2  Oxidation of Dihydropyridine 4  
     (R 1 ═CO 2 Me; R 2 =4-(dimethylamino)phenyl; R 3 ═H; R 4 =Me)  
       [0133]     To a solution of dihydropyridine 4 (0.50 g, 1.3 mmol) in 10 mL of dichloromethane was added manganese dioxide (2.5 g, 28.7 mmol). The reaction was stirred at room temperature overnight before filtering and washing with dichloromethane. The filtrate was concentrated to yield 0.43 g (88%) of orange solid 1. MS m/z 395 (M + +23), 373 (M + +1).  
       EXAMPLE 8  
     Cleavage of Carboxylic Ester 5  
     (R 2 =2,4-dimethylphenyl; R 3 ═H; R 4 =Me)  
       [0134]     To a suspension of ester 5 (2.75 g, 6.94 mmol) in acetone (50 mL) was added aqueous 1 M NaOH (100 mL). After stirring at room temperature for 24 hours, the reaction mixture was diluted with 100 mL of water and washed with dichloromethane (2×100 mL). The aqueous layer was cooled to 0° C. and acidified with concentrated HCl. The mixture was filtered and washed with water to yield 1.84 g (77%) yellow solid 6. MS m/z 366 (M + +23), 343 (M + +1).  
       EXAMPLE 9  
     Preparation of Amide 7  
     (R 2 =2,4-dimethylphenyl; R 3 ═H; R 4 =Me; R 5 ═H: R 6 =Me)  
       [0135]     A solution of carboxylic acid 6 (0.337 g, 0.98 mmol) in thionyl chloride (10 mL) was heated at reflux for 1 hour. The solution was cooled and concentrated in vacuo. The residue was diluted with CCl 4  and concentrated to remove the residual thionyl chloride. The residue was then dissolved in THF (3.5 mL) and added to a 0° C. solution of methylamine (1.47 mL of 2.0 M solution in THF, 2.94 mmol) in 6.5 mL THF. The reaction was warmed to room temperature and stirred overnight. The mixture was poured into water, filtered, washed with water and dried to yield 0.263 g (75%) of tan solid. MS m/z 357 (M + +1).  
       EXAMPLE10  
     Preparation of Pyridine 1  
     (R 1 ═CO 2 Et; R 2 =4-nitrophenyl; R 3 ═H; R 4 ═NH 2 )  
       [0136]     To a refluxing solution of benzylidene 2 (1.05 g, 3.76 mmol) in 10 mL of acetic acid was added ethyl amidinoacetate acetic acid salt (0.720 g, 3.76 mmol). The resulting solution was heated at reflux overnight. After cooling to room temperature, the resulting precipitate was removed by filtration and washed with water. This impure residue was heated in a minimal amount of ethanol and then filtered to yield 0.527 g (35%) of a yellow solid. MS m/z 412 (M + +23), 390 (M + +1).  
       EXAMPLE 11  
     Hantzsch Condensation of Benzylidene 8  
     (R 2 =3-methoxyphenyl) and 1,3-indandione)  
       [0137]     The benzylidene 8 (2.00 g, 9.2 mmol), 1,3-indandione (1.34 g, 0.2 mmmol) and ammonium acetate (2.83 g, 36.7 mmol) were added to 30 mL of ethanol and heated to reflux overnight. The reaction mixture was cooled to room temperature and diluted with ethanol. A yellow precipitate was collected by filtration, washed with ethanol, and dried under vacuum to yield 1.98 g (63%) of the dihydropyridine 9. MS m/z 346 (M + +1).  
       EXAMPLE 12  
     Reduction to Prepare Amine 11  
     (R 1 ═CO 2 Me; R 2 =4-methylnaphthyl; R 4 =Me)  
       [0138]     To a refluxing suspension of pyridine 10 (0.862 g, 1.97 mmol) in 35 mL of ethanol was added a solution of tin (II) chloride dihydrate (1.33 g, 5.90 mmol) in 6 mL of 1:1 ethanol: concentrated HCl. The resulting solution was heated at reflux overnight. Water was added until a precipitate started to form and the reaction was cooled to room temperature. The mixture was then filtered and washed with water. After drying, the residue was purified by column chromatography eluting with hexanes: ethyl acetate to yield 0.551 g (69%) of an orange solid. MS m/z 431 (M + +23), 409 (M + +1).  
       EXAMPLE 13  
     Acetylation of Amine 11  
     (R 1 ═CO 2 Et; R 2 =3,4-methylenedioxyphenyl; R 4 =Me)  
       [0139]     To a solution of amine 11 (0.070 g, 0.174 mmol) in 15 mL of dichloromethane was added triethylamine (0.026 g, 0.261 mmol) and acetyl chloride (0.015 g, 0.192 mmol). After stirring overnight at room temperature, the reaction mixture was diluted with water and then extracted with dichloromethane (3×35 mL). The combined organics were washed with brine, dried over MgSO 4 , and concentrated. The residue was purified by silica gel chromatography eluting with hexanes: ethyl acetate to yield 0.054 g (70%) of amide 12. MS m/z 467 (M + +23), 445 (M + +1).  
       EXAMPLE 14  
     Preparation of Carboxylic Acid 13  
     (R 1 ═CO 2 Me: R 2 =3,5-dimethylphenyl; R 4 =Me; Y═O; n=2)  
       [0140]     To a suspension of amine 11 (0.079 g, 0.212 mmol) in 5 mL of benzene was added succinic anhydride (0.021 g, 0.212 mmol). After heating at reflux for 24 hours, the reaction mixture was filtered and washed with benzene. The residue was dried under high vacuum and then washed with ether to remove the excess succinic anhydride. This yielded 0.063 g (63%) of carboxylic acid 13. MS m/z 473 (M + +1).  
       EXAMPLE 15  
     Preparation of Carboxylic Acid 13  
     (R 1 ═CO 2 Me: R 2 =3,5-dimethylphenyl; R 4 =Me; Y═H 2 : n=1)  
       [0141]     To a refluxing solution of amine 11 (0.078 g, 0.210 mmol) in 5 mL of acetonitrile was added β-propiolactone (0.015 g, 0.210 mmol). The reaction was heated to reflux for 72 hours before cooling to room temperature. The reaction mixture was concentrated. The residue was mixed with 10% aqueous sodium hydroxide and washed sequentially with ether and ethyl acetate. The aqueous layer was acidified with concentrated HCl and extracted with dichloromethane (2×25 mL). The combined organics were dried over MgSO 4 , filtered, and concentrated. The residue was purified by column chromatography eluting with 5% MeOH in dichloromethane to yield 0.020 g (21%) of an orange solid. MS m/z 467 (M + +23), 445 (M + +1).  
       EXAMPLE 16  
     Preparation of Hydroxamic Acid 14  
     (R 1 ═CO 2 Me; R 2 =(4-methyl)-1-naphthyl; Y═O; n=2; R 4 =Me)  
       [0142]     To a 0° C. suspension of carboxylic acid 13 (.0.054 g, 0.106 mmol) in 10 mL of diethyl ether was added triethylamine (0.014 g, 0.138 mmol) and then ethyl chloroformate (0.014 g, 0.127 mmol). The mixture was stirred at 0° C. for 30 minutes and them warmed to room temperature. A solution of hydroxylamine (0.159 mmol) in methanol was added and the reaction was stirred overnight at room temperature. The mixture was filtered and the residue was washed with ether and dried under vacuum to yield 0.030 g (54%) of a yellow solid. MS m/z 524 (M + +1).  
       EXAMPLE 17  
     Preparation of Amide 15  
     (R 1 ═CO 2 Me; R 2 =3,5-dimethylphenyl; R 4 =Me)  
       [0143]     A mixture of amine 11 (0.201 g, 0.54 mmol) and glycolic acid (0.049 g, 0.65 mmol) was heated at 120-160° C. for 30 minutes. During heating, more glycolic acid was added to ensure that excess reagent was present. Once the starting material was consumed, the reaction was cooled to room temperature, and diluted with dichloromethane. The resulting mixture was extracted with 20% NaOH, followed by 10% HCl, and finally water. The combined organics were concentrated and triturated with ether. Purification by column chromatography eluting with ethyl acetate:hexanes yielded 0.012 g (5%) of a yellow solid. MS m/z 453 (M + +23), 431 (M + +1).  
       EXAMPLE 18  
     Preparation of Amide 16  
     (R 1 ═CO 2 Me; R 2 =3,5-dimethylphenyl; R 4 =Me: NR 6 R 7 =morpholino)  
       [0144]     To a 0° C. mixture of amine 11 (0.123 g, 0.331 mmol) in 2 mL of 20% aqenius NaHCO 3  and 3 mL of ethyl acetate was added chloroacetyl chloride (0.047 g, 0.413 mmol). The reaction was warmed to room temperature and stirred for 45 minutes. The mixture was poured into a separatory funnel and the aqueous layer was removed. The organic layer containing the crude chloroamide was used without purification. To the ethyl acetate solution was added morpholine (0.086 g, 0.992 mmol) and the reaction was heated to approx. 65° C. overnight. The reaction was diluted with water and cooled to room temperature. After extraction with ethyl acetate (3×25 mL), the combined organics were washed with brine, dried over MgSO 4  and concentrated to yield 0.130 g (79%) of a yellow solid. MS m/z 522 (M + +23), 500 (M + +1).  
       EXAMPLE 19  
     Preparation of Piperazinone 17  
     (R 1 ═CO 2 Me: R 2 =3,5-dimethylphenyl; R 4 =Me; R 7 ═H)  
       [0145]     To a 0° C. solution of amide 16 (R 6 ═CH 2 CH 2 OH) (0.093 g, 0.20 mmol), tri n-butylphosphine (0.055 g, 0.27 mmol) in 0.35 mL ethyl acetate was slowly added di-tert-butyl azodicarboxylate (0.062 g, 0.27 mmol) in 0.20 mL ethyl acetate. The reaction was allowed to stand for 15 minutes and then heated to 40° C. overnight. 4.2 M ethanolic HCl was added dropwise. The mixture was cooled to 0° C. and allowed to stand for 2 hours. The mixture was filtered and washed with cold ethyl acetate. Purification by column chromatography with 1-5% MeOH in CH 2 Cl 2  yielded 0.011 (12%) of a white solid. MS m/z 478 (M + +23), 456 (M + +1).  
       EXAMPLE 20  
     Preparation of 4-Aminoindenopyridine 19  
     (R 1 ═CO 2 Me; R 4 =Me; R 6 =Me; R 7 =phenyl)  
       [0146]     To a solution of 4-chloroindenopyridine 18 (0.069 g, 0.240 mmol) in 10 mL of 2-ethoxyethanol was added N-methylaniline (0.026 g, 0.240 mmol). The reaction was heated at reflux for 96 hours. After cooling to room temperature, the solution was concentrated. The residue was purified by column chromatography eluting with hexanes: ethyl acetate to yield 0.029 g (34%) of an orange solid. MS m/z 359 (M + +1).  
       EXAMPLE 21  
     Preparation of 4-Aminoindenopyridine 19  
     (R 1 ═CO 2 Me: R 4 =Me; R 6 ═H: R 7 =cyclopentyl) by Palladium Catalyzed Coupling  
       [0147]     A mixture of 4-chloroindenopyridine 18 (0.100 g, 0.347 mmol), cyclopentylamine (0.035 g, 0.416 mmol), palladium (II) acetate (0.004 g, 0.0017 mmol), 2-(di-t-butylphosphino)biphenyl (0.010 g, 0.0035 mmol), and cesium carbonate (0.124 g, 0.382 mmol) in 10 mL of dioxane was heated at reflux overnight. The reaction was cooled to room temperature, diluted with water, and extracted with ethyl acetate (3&#39;35 mL). The combined organics were washed with brine, dried over Na 2 SO 4 , and concentrated. The residue was purified by column chromatography eluting with ethyl acetate:hexanes. The purified oil was dissolved in ether and cooled to 0° C. To this solution was slowly added 1.0 M HCl in ether. The resulting precipitate was isolated by filtration, washed with ether, and dried under vacuum to yield 0.032 g (25%) of a yellow solid. MS m/z 359 (M + +23), 337 (M + +1).  
       EXAMPLE 22  
     Preparation of Dihydropyridine 21 (R 1 ═CO 2 Me: R 2 =2-furyl; R 3 ═H; R 4 ═NH 2 )  
       [0148]     Unsaturated cyanoester 20 (0.20 g, 1.10 mmol), enamine 21 (0.20 g, 0.75 mmol) and 5 drops of triethylamine were refluxed in 1-propanol (4 mL). After 3 hours, the reaction was concentrated to half the volume and cooled. The resulting precipitate was filtered and washed with 1-propanol. The precipitate was a mixture of products and therefore was combined with the filtrate and concentrated. Purification by column chromatography, eluting with ethyl acetate: hexane yielded 0.11 g (34%) of the red product 22. MS m/z 465 (M + +23).  
       EXAMPLE 23  
     DDQ Oxidation/Deprotection of Dihydropyridine 22  
     (R 1 ═CO 2 Me; R 2 =3-furyl; R 3 ═H; R 4 ═NH 2 )  
       [0149]     To a solution of dihydropyridine 22(0.05 g, 0.11 mmol) in chlorobenzene (4 mL) was added 2,3-dichloro-3,6-dicyano-1,4-benzoquinone (0.05 g, 0.22 mmol). The reaction was refluxed overnight before cooling to room temperature and diluting with diethyl ether. The reaction mixture was filtered through celite and concentrated in vacuo. Purification by column chromatography, eluting with ethyl acetate:hexane yielded 0.018 g (52%) of yellow product 23. MS m/z 343 (M + +23), 321 (M + +1).  
         [0150]     Following the general synthetic procedures outlined above and in Examples 1-21, the compounds of Table 1 below were prepared.  
                                                                                               TABLE 1                               Ia                                                                                      MS       No.   R 1     R 2     R 3a     R 3b     R 3c     R 3d     R 4     (M + 1)                                                            1   CN                                 H   H   H   H   Me   341               2   CO 2 Et                                 H   H   H   H   Me   388               3   CO 2 t-Bu                                 H   H   H   H   Me   416               4   CO 2 t-Bu                                 H   H   H   H   Me   432               5   CO 2 Et                                 H   H   H   H   Me   389               6   CO 2 H                                 H   H   H   H   Me   360               7   CO 2 Et                                 H   H   H   H   Me   480               8   CO 2 Et                                 H   H   H   H   Me   482               9   CO 2 Et                                 H   H   H   H   Me   424               10   CO 2 H                                 H   H   H   H   Me   376               11   CO 2 Et   Ph   H   H   H   H   Me   344               12   CO 2 Et                                 H   H   H   H   Me   374               13   CO 2 Et                                 H   H   H   H   Me   434               14   CO 2 Et                                 H   H   H   H   Me   454               15   CO 2 Bn                                 H   H   H   H   Me   450               169                                                               H   H   H   H   Me   507               17   CO 2 Me                                 H   H   H   H   Me   390               18   CO 2 Me                                 H   H   H   H   Me   374               19   CO 2 Et                                 H   H   H   H   Me   404               20   CO 2 Et                                 H   H   H   H   Me   404               21   CO 2 Et                                 H   H   H   H   Me   454               22   CO 2 Et                                 H   H   H   H   NH 2     411 (M + 23)               23   CO 2 Et                                 H   H   H   H   Me   388               25   CO 2 Et                                 H   H   H   H   NH 2     405               26   CO 2 Et                                 H   H   H   H   NH 2     390               27   CO 2 Et   Ph   H   H   H   H   NH 2     345               28   CO 2 Et                                 H   H   H   H   Me   402               29   CO 2 Et                                 H   H   H   H   Me   483               30   CO 2 Me   Ph   H   H   H   H   Me   330               31   CO 2 Et                                 H   H   H   H   Me   402               32   CO 2 Et                                 H   NO 2     H   H   Me   433               33                                                               H   H   H   H   Me   413               34   CO 2 Et                                 H   H   H   H   Me   433               35   CO 2 Et                                 H   H   NO 2     H   Me   433               36   CO 2 Me                                 H   H   H   H   Me   398               37   CO 2 Et                                 H   H   NH 2     H   Me   403               38   CONH 2                                   H   H   H   H   Me   359               39   CO 2 Et                                 H   H   H   H   Me   372               40   CO 2 Et                                 H   NH 2     H   H   Me   403               41   CO 2 Et                                 H   H   H   H   Me   334               42   CO 2 Et   2-Thienyl   H   H   H   H   Me   350               43   CO 2 Me                                 H   H   H   H   Me   358               44   CO 2 Me                                 H   H   H   H   Me   388               45   CO 2 Me                                 H   H   H   H   Me   419               46   CO 2 Me                                 H   H   H   H   Me   388               47   CO 2 Me   4-Pyridyl   H   H   H   H   Me   331               48   CO 2 Me                                 H   H   H   H   Me   374               49   CO 2 Me                                 H   H   H   H   Me   454               50   CO 2 Me                                 H   H   H   H   Me   439               51   CO 2 Me                                 H   H   H   H   Me   358               52   CO 2 Et                                 H   H   H   H   Me   372               53   CO 2 Me                                 H   H   H   H   Me   410               54   CO 2 Me                                 H   H   H   H   Me   375               55   CO 2 Et                                 H   NHAc   H   H   Me   445               56   CO 2 Et                                 H   H   NHAc   H   Me   445               57   CO 2 Et                                 H   H   H   H   Me   358               58   CO 2 Et                                 H   H   H   H   Me   358               59   CO 2 Et                                 H   H   H   H   Me   358               60   CO 2 Et                                 H   NO 2     H   H   Me   457               61   CO 2 Et                                 H   H   NO 2     H   Me   457               62   CO 2 Me                                 H   H   H   H   Me   344               63   CO 2 Et                                 H   NH 2     H   H   Me   427               64   CO 2 Et                                 H   H   NH 2     H   Me   427               65   CO 2 Me                                 H   H   H   H   Me   466               66   CO 2 Me                                 H   H   H   H   Me   344               67   CO 2 Me                                 H   H   H   H   Me   344               68   CO 2 Me                                 H   NO 2     H   H   Me   443               69   CO 2 Me                                 H   H   NO 2     H   Me   443               70   CO 2 Et                                 H   H   H   H   i-Pr   400               71   CO 2 Me                                 H   NH 2     H   H   Me   413               72   CO 2 Me                                 H   H   H   H   Me   399               73   CO 2 Me                                 H   H   H   H   Et   372               74   CO 2 Me                                 H   H   H   H   Me   398               75   CO 2 Me                                 H   H   H   H   Me   394               76   CO 2 Me                                 H   H   H   H   Me   372               77   CO 2 Me                                 H   NO 2     H   H   Me   403               78   CO 2 Me                                 H   H   NO 2     H   Me   403               79   CO 2 Me                                 H   H   H   H   Me   394               80   CO 2 Me                                 H   NHAc   H   H   Me   455               81   CO 2 Me                                 H   H   H   H   Me   488               82   CO 2 Me                                 H   NH 2     H   H   Me   373               83   CO 2 Me                                 H   H   NH 2     H   Me   373               84   CO 2 Me                                 H   H   H   H   Me   362               85   CO 2 Me                                 H   H   H   H   Me   431 (M + 23)               86   CO 2 Me                                 H   H   H   H   Me   380 (M + 23)               87   CO 2 Me                                 H   NO 2     H   H   Me   439               88   CO 2 Me                                 H   H   NO 2     H   Me   439               89   CO 2 Me                                 H   H   H   H   Me   430               90   CO 2 Me                                 H   NH 2     H   H   Me   409               91   CO 2 Me                                 H   H   NH 2     H   Me   409               92                                                               H   H   H   H   Me   397               93   CN                                 H   H   H   H   Me   325               94   CO 2 Me                                 H   H   H   H   NH 2     359               95   CO 2 Me                                 H   H   H   H   NH 2     395               96   CO 2 H                                 H   H   H   H   Me   344               97                                                               H   H   H   H   Me   433               98   CN                                 H   H   H   H   Me   361               99                                                               H   H   H   H   C 2 H 2 O 2     358               100                                                               H   H   H   H   C 2 H 2 O 2     357               101                                 Ph   H   H   H   H   C 2 H 2 O 2     314               102                                 p-C 6 H 4 NO 2     H   H   H   H   C 2 H 2 O 2     361               103                                                               H   H   H   H   C 2 H 2 O 2     364               104                                                               H   H   H   H   C 2 H 2 O 2     342               105   CO 2 H                                 H   H   H   H   Me   380               106   CONH 2                                   H   H   H   H   Me   343               107   CONHMe                                 H   H   H   H   Me   357               108   CONMe 2                                   H   H   H   H   Me   371               109                                                               H   H   H   H   C 2 H 2 O 2     378               110                                                               H   H   H   H   C 2 H 2 O 2     328               111                                                               H   H   H   H   C 2 H 2 O 2     356               112                                                               H   H   H   H   C 2 H 2 O 2     328               113   CO 2 Me                                 H   H   H   H   Me   375               114                                                               H   H   H   H   C 2 H 2 O 2     328               115   CO 2 Me                                 H   H   H   H   Me   373               116   CONH 2                                   H   H   H   H   Me   379               117                                                               H   H   H   H   C 2 H 2 O 2     365               118   CO 2 Me                                 H   H   H   H   Me   375               119   CONHMe                                 H   H   H   H   Me   393               120   CONMe2                                 H   H   H   H   Me   407               121   CO 2 Me                                 H   H   H   H   Me   381               122   CO 2 Me                                 H   Cl   Cl   H   Me   463               123   CO 2 Me                                 H   Cl   Cl   H   Me   427               124   CO 2 Me                                 H   H   H   H   Me   381               125   CO 2 Et                                 H   H   H   H   Me   408               126   CO 2 Me                                 H   Cl   Cl   H   Me   555               127   CO 2 Me                                 Cl   H   H   Cl   Me   427               128   CO 2 Me   2-NO 2 -4,5-OCH 2 O—C 6 H 2     H   H   H   H   Me   421               129   CO 2 Me                                 Cl   H   H   Cl   Me   558               130   CO 2 Me                                 H   H   H   H   Me   345               131   CO 2 Et                                 H   Cl   Cl   H   Me   477               132   CO 2 Me                                 H   H   H   H   Me   503               133   Ac                                 H   H   H   H   Me   472               134   Ac                                 H   H   H   H   Me   342               135   CO 2 Me                                 H   H   H   H   Me   331               136                                                               H   H   H   H   Me   527               137                                                               H   H   H   H   Me   397               138   CO 2 Me                                 H   H   H   H   Me   362               139   CO 2 H                                 H   H   H   H   Me   474               140   CO 2 H                                 H   H   H   H   Me   344               141   CO 2 Me                                 H   H   H   H   Me   346               142   CO 2 Me                                 H   H   H   H   Me   380               143   CO 2 Me                                 H   H   H   H   Me   486               144   CO 2 Me                                 H   H   H   H   Me   436               145   CO 2 Me                                 H   H   H   H   Me   518               146                                                               H   H   H   H   Me   557               147                                                               H   Cl   Cl   H   Me   466               148   CO 2 Et   —NHPh   H   H   H   H   Me   359               149   CO 2 Me                                 H   H   H   H   Me   360               150   CO 2 Me                                 H   H   H   H   Me   504               151                                                               H   H   H   H   Me   420               152   C 3 H 5 O 3                                   H   H   H   H   Me   534               153                                                               H   H   H   H   Me   385               154                                                               H   H   H   H   Me   373               155                                                               H   H   NO 2     H   Me   574               156   CO 2 Me                                 H   Br   H   H   Me   473               157   CO 2 Me                                 H   H   Br   H   Me   473               158                                                               H   Cl   Cl   H   Me   489               159                                                               H   H   NO 2     H   Me   590               160                                                               H   H   H   H   Me   411               161   CO 2 Me                                 H   Br   H   H   Me   436               162   CO 2 Me                                 H   H   Br   H   Me   438               163   CO 2 Me                                 H   Br   Br   H   Me   516               164                                                               H   Cl   Cl   H   Me   597               165                                                               H   Cl   Cl   H   Me   480               166   CO 2 Me                                 H   Br   Br   H   Me   552               167   CO 2 Et                                 H   Br   Br   H   Me   530               168   CO 2 Me                                 F   H   H   F   Me   540               169   CO 2 Me                                 H   H   NO 2     H   Me   551               170   CO 2 Me                                 H   Cl   Cl   H   Me   573               171                                                               H   H   NO 2     H   Me   444               172                                                               H   NO 2     H   H   Me   444               173   CO 2 Me                                 F   H   H   F   Me   394               174                                                               F   H   H   F   Me   433               175   CO 2 Me                                 H   Br   Br   H   Me   548               176   CO 2 Me                                 H   H   H   H   Me   355               177   CO 2 Me                                 H   NO 2     H   H   Me   421               178   CO 2 Me                                 H   H   NO 2     H   Me   453 (M + 23)               179   CO 2 Me                                 H   Cl   Cl   H   Me   443               180   CN                                 H   H   H   H   Me   341               181   CO 2 Me                                 H   H   H   H   Me   598               182   CO 2 Me                                 H   Cl   Cl   H   Me   435               183   CO 2 Et                                 H   H   H   H   Me   387               184   CO 2 Et                                 H   H   H   H   Me   373               185   CO 2 Me                                 H   H   H   H   Me   612               186   CO 2 Et                                 H   H   H   H   Me   410               187   CO 2 Me                                 H   H   NO 2     H   Me   345               188   CO 2 Me                                 H   Cl   Cl   H   Me   668               189   CO 2 Me                                 H   H   NO 2     H   Me   413               190   CO 2 H                                 H   Cl   Cl   H   Me   544               191   CN                                 H   H   H   H   Me   565               192   CO 2 Me                                 H   Br   H   H   Me   606 (M + 23)               193   CO 2 Me                                 H   H   Br   H   Me   584               194   CO 2 Et                                 H   H   H   H   Me   373               195   CO 2 Et                                 H   H   H   H   Me   427               196   CO 2 Et                                 H   Cl   Cl   H   Me   587               197   CO 2 Et                                 H   H   H   H   Me   437               198   CO 2 Et                                 H   H   H   H   Me   389               199   CO 2 Et                                 H   H   H   H   Me   612               200   CO 2 Et                                 H   Cl   Cl   H   Me   449               201   CO 2 Me                                 H   Cl   Cl   H   Me   450               202   CO 2 Me                                 H   Cl   Cl   H   Me   465               203   CO 2 Me                                 H   H   H   H   Me   396               204   CO 2 Me                                 H                                 H   H   Me   473               205   CO 2 Me                                 H   H   H   H   Me   345               206   CO 2 Me                                 H   H   H   H   Me   359               207   CO 2 Me                                 H   Cl   Cl   H   Me   444               208   CO 2 Me                                 H   H   H   H   Me   355               209   CO 2 H                                 H   H   H   H   Me   366               210   CO 2 Me                                 H   Cl   Cl   H   Me   444               211   CO 2 Me                                 H   Cl   Cl   H   Me   430               212   CO 2 Me                                 H   H   H   H   Me   416               213   CO 2 Me                                 H   Cl   Cl   H   Me   430               214   CO 2 Me                                 H   H   H   H   Me   413               215   CO 2 Me                                 H   OMe   OMe   H   Me   418               216   CO 2 Me                                 H   OMe   OMe   H   Me   454               217   CO 2 Me                                 H   H   H   H   Me   362               218   CO 2 Me                                 H                                 H   H   Me   445               219   CO 2 Me                                 H   H   H   H   Me   359               220   CO 2 Me   —NHPh   H   H   H   H   Me   345               221   CO 2 Me                                 H   H   H   H   Me   423               222   CO 2 Me   2-Pyridyl   H   H   H   H   Me   353 (M + 23)               223   CO 2 Me                                 H   OMe   OMe   H   Me   459               224   CO 2 Me                                 H   Cl   Cl   H   Me   485               225   CO 2 Me                                 H   H   H   H   Me   345               226   CO 2 Me                                 H   H   NO 2     H   Me   420               227   CO 2 Me                                 H   H   NO 2     H   Me   420               228   CO 2 Me                                 H   H   H   H   Me   359               229   CO 2 Me                                 H   H   H   H   Me   396               230   CO 2 Me                                 H   OH   OH   H   Me   426               231   CO 2 Me                                 H   H   F   H   Me   376               232   CO 2 Me                                 H   H   NO 2     H   Me   461               233   CO 2 Me                                 H   Cl   Cl   H   Me   468               234   CO 2 Me                                 H   H   H   H   Me   373               235   CO 2 Me                                 H   H   H   H   Me   375               236   CO 2 Me                                 H   NO 2     H   H   Me   443               237   CO 2 Me                                 H   H   NO 2     H   Me   443               238   CO 2 Me                                 H   H   H   H   Me   398               239   CO 2 Me                                 H   Cl   Cl   H   Me   491               240   CO 2 Me                                 H                                 H   H   Me   509               241   CO 2 Me                                 H   H                                 H   Me   473               242   CO 2 Me                                 H   H                                 H   Me   509               243   CO 2 Me                                 H   H   H   H   Me   310               244   CO 2 Me                                 H                                 H   H   Me   524               245   CO 2 Me                                 H   H                                 H   Me   488               246   CO 2 Me                                 H   H   H   H   Me   308               247   CO 2 Me   i-Pr   H   H   H   H   Me   296               248   CO 2 Me                                 H   H   H   H   Me   336               249   CO 2 Me   Me   H   H   H   H   Me   268               250   CO 2 Me                                 H   H                                 H   Me   474               251   CO 2 Me                                 H   H                                 H   Me   487               252   CO 2 Me   N-Morpholino   H   H   H   H   Me   339               253   CO 2 Me                                 H   H   H   H   Me   337               254   CO 2 Me                                 H   H                                 H   Me   488               255   CO 2 Me                                 H                                 H   H   Me   474               256   CO 2 Me                                 H                                 H   H   Me   456               257   CO 2 Me                                 H                                 H   H   Me   431               258   CO 2 Me                                 H                                 H   H   Me   500               259   CO 2 Me                                 H                                 H   H   Me   499               260   CO 2 Me                                 H                                 H   H   Me   481               261   CO 2 Me                                 H   H                                 H   Me   500               262   CO 2 Me                                 H   H                                 H   Me   499               263   CO 2 Me                                 H   H                                 H   Me   431               264   CO 2 Me                                 H   H   H   H   NH 2     397 (M + 23)               265   CO 2 Me   H   H   H   H   NH 2     353                                       (M + 23)               266   CO 2 Me                                 H   H   H   H   NH 2     413 (M + 23)               267   CO 2 Me   2-Furyl   H   H   H   H   NH 2     321       268   CO 2 Me   3-Furyl   H   H   H   H   NH 2     321       269   CO 2 Me   2-Furyl   H   H   H   H   Me   320       270   CO 2 Me   2-Furyl   H   H   H   NH 2     Me   335       271   CO 2 Me   2-Furyl   NHOH   H   H   H   Me   351       272   CO 2 Et   2-Furyl   H   H   H   H   NH 2     335       273   CO 2 Et   2-Furyl   H   Br   H   H   NH 2     413       274   CO 2 Et   2-Furyl   H   H   Br   H   NH 2     413               275   CO 2 Et                                 H   H   H   H   Me   467               276   CO 2 Me                                 H   H                                 H   Me   481               277   CO 2 Me                                 H   H                                 H   Me   456               278   CO 2 Me                                 H                                 H   H   Me   473               279   CO2Me                                 H                                 H   H   Me   513               280   CO 2 Me                                 H                                 H   H   Me   516               281   CO 2 Me                                 H                                 H   H   Me   501               282   CO 2 Me                                 H                                 H   H   Me   566               283   CO 2 Me                                 H                                 H   H   Me   488               284   CO 2 Me                                 H   H                                 H   Me   541                  
 
 III. Biological Assays and Activity 
 
 Ligand Binding Assay for Adenosine A2a Receptor 
 
         [0151]     Ligand binding assay of adenosine A2a receptor was performed using plasma membrane of HEK293 cells containing human A2a adenosine receptor (PerkinElmer, RB-HA2a) and radioligand [ 3 H]CGS21680 (PerkinElmer, NET1021). Assay was set up in 96-well polypropylene plate in total volume of 200 mL by sequentially adding 20 mL 1:20 diluted membrane, 130 mL assay buffer (50 mM Tris.HCl, pH7.4 10 mM MgCl 2 , 1 mM EDTA) containing [ 3 H] CGS21680, 50 mL diluted compound (4×) or vehicle control in assay buffer. Nonspecific binding was determined by 80 mM NECA. Reaction was carried out at room temperature for 2 hours before filtering through 96-well GF/C filter plate pre-soaked in 50 mM Tris.HCl, pH7.4 containing 0.3% polyethylenimine. Plates were then washed 5 times with cold 50 mM Tris.HCl, pH7.4., dried and sealed at the bottom. Microscintillation fluid 30 ml was added to each well and the top sealed. Plates were counted on Packard Topcount for [ 3 H]. Data was analyzed in Microsoft Excel and GraphPad Prism programs. (Varani, K.; Gessi, S.; Dalpiaz, A.; Borea, P. A. British Journal of Pharmacology, 1996, 117, 1693)  
         [0000]     Adenosine A2a Receptor Functional Assay  
         [0152]     CHO-K1 cells overexpressing human adenosine A2a receptors and containing cAMP-inducible beta-galactosidase reporter gene were seeded at 40-50K/well into 96-well tissue culture plates and cultured for two days. On assay day, cells were washed once with 200 mL assay medium (F-12 nutrient mixture/0.1% BSA). For agonist assay, adenosine A2a receptor agonist NECA was subsequently added and cell incubated at 37 C, 5% CO 2  for 5 hrs before stopping reaction. In the case of antagonist assay, cells were incubated with antagonists for 5 minutes at R.T. followed by additon of 50 nM NECA. Cells were then incubated at 37 C, 5% CO 2  for 5 hrs before stopping experiments by washing cells with PBS twice. 50 mL 1× lysis buffer (Promega, 5× stock solution, needs to be diluted to 1× before use) was added to each well and plates frozen at −20 C. For b-galactosidase enzyme colormetric assay, plates were thawed out at room temperature and 50 mL 2× assay buffer (Promega) added to each well. Color was allowed to develop at 37 C for 1 hr. or until reasonable signal appeared. Reaction was then stopped with 150 mL 1 M sodium carbonate. Plates were counted at 405 nm on Vmax Machine (Molecular Devices). Data was analyzed in Microsoft Excel and GraphPad Prism programs. (Chen, W. B.; Shields, T. S.; Cone, R. D. Analytical Biochemistry, 1995, 226, 349; Stiles, G. Journal of Biological Chemistry, 1992, 267, 6451)  
         [0000]     Assay of Phosphodiesterase Activity  
         [0153]     The assay of phosphodiesterase activity follows the homogeneous SPA (scintillation proximity assay) format under the principle that linear nucleotides preferentially bind yttrium silicate beads in the presence of zinc sulfate.  
         [0154]     In this assay, the enzyme converts radioactively tagged cyclic nucleotides (reaction substrate) to linear nucleotides (reaction product) which are selectively captured via ion chelation on a scintillant-containing bead. Radiolabeled product bound to the bead surface results in energy transfer to the bead scintillant and generation of a quantifiable signal. Unbound radiolabel fails to achieve close proximity to the scintillant and therefore does not generate any signal.  
         [0155]     Specifically, enzyme was diluted in PDE buffer (50 mM pH 7.4 Tris, 8.3 mM MgCl 2 , 1.7 mM EGTA) with 0.1% ovalbumin such that the final signal:noise (enzyme:no enzyme) ratio is 5-10. Substrate (2,8- 3 H-cAMP or 8- 3 H-cGMP, purchased from Amersham Pharmacia) was diluted in PDE (4, 5, 7A) buffer to 1 nCi per μl (or 1 μCi/ml). For each test well, 48 μl of enzyme was mixed with 47 μl substrate and 5 μl test compound (or DMSO) in a white Packard plate, followed by shaking to mix and incubation for 15 minutes at room temperature. A 50 μl aliquot of evenly suspended yttrium silicate SPA beads in zinc sulfate was added to each well to terminate the reaction and capture the product. The plate was sealed using Topseal-S (Packard) sheets, and the beads were allowed to settle by gravity for 15-20 minutes prior to counting on a Packard TopCount scintillation counter using a  3 H glass program with color quench correction. Output was in color quench-corrected dpm.  
         [0156]     Test compounds were diluted in 100% DMSO to a concentration 20× final assay concentration. DMSO vehicle alone was added to uninhibited control wells. Inhibition (%) was calculated as follows:  
         Nonspecific   ⁢           ⁢   binding   ⁢           ⁢     (   NSB   )       =       the   ⁢           ⁢   mean   ⁢           ⁢   of   ⁢           ⁢   CPM   ⁢           ⁢   of   ⁢           ⁢   the   ⁢           ⁢   substrate     +   buffer   +     DMSO   ⁢           ⁢   wells           
         Total   ⁢           ⁢   Binding   ⁢           ⁢     (   TB   )       =       the   ⁢           ⁢   mean   ⁢           ⁢   of   ⁢           ⁢   the   ⁢           ⁢   enzyme     +   substrate   +     DMSO   ⁢           ⁢   wells           
         %   ⁢           ⁢     i   ⁢   nhibition     ⁢           ⁢   listed   ⁢           ⁢   in   ⁢           ⁢   Table   ⁢           ⁢   1     =       (     1   -       (       Sample   ⁢           ⁢   CPM     -   NSB     )       TB   -   NSB         )     ×   100         
 
         [0157]     The IC 50  values were calculated using the Deltagraph 4-parameter curve-fitting program. The IC 50  and % Inhibition data on PDE 4, 5, and 7A are listed for the indicated compounds in Table 2 below.  
                                                                                                                                     TABLE 2                               Ia                                                          MS   IC 50  (μM) / % inh.@μM            No.   R 1     R 2     R 3a     R 3b     R 3c     R 3d     R 4     (M + 1)   PDE7A   PDE4   PDE5                                                                        6   CO 2 H                             
C 7 H 5 O 2     H   H   H   H   Me   360   45% @20   49%@5               51   CO 2 Me                             
C 8 H 9     H   H   H   H   Me   358   0.055   0.353   2.7               56   CO 2 Et                             
C 7 H 5 O 2     H   H   NHAc   H   Me   445   0.074   0.333   2.5               70   CO 2 Et                             
C 8 H 9     H   H   H   H   i-Pr   400   2.11               73   CO 2 Me                             
C 8 H 9     H   H   H   H   Et   372   1.54       0.998               82   CO 2 Me                             
C 8 H 9     H   NH 2     H   H   Me   373   0.021   0.204   1.11, 0.864               90   CO 2 Me                             
C 11 H 9     H   NH2   H   H   Me   409   0.005   0.237, 0.172   2.33               98   CN                             
C 11 H 9     H   H   H   H   Me   361   1.13               119   CONHMe                             
C 11 H 9     H   H   H   H   Me   393   0.658       41% @20               133   Ac                             
C 6 H 3 Br 2     H   H   H   H   Me   472   1.54               134   Ac                             
C 8 H 9     H   H   H   H   Me   342   1.14               169   CO 2 Me                             
C 6 H 3 Br 2 O   H   H   NO 2     H   Me   551   0.0053       0.184               170   CO 2 Me                             
C 6 H 3 Br 2 O   H   Cl   Cl   H   Me   573   0.0087       0.557               190   CO 2 H                             
C 6 H 3 Br 2     H   Cl   Cl   H   Me   544   5.9               191   CN                             
C 6 H 3 I 2 O   H   H   H   H   Me   565   0.593               197   CO 2 Et                             
C 6 H 5 BrN   H   H   H   H   Me   437   0.728   69% @5   0.362               219   CO 2 Me                             
C 7 H 8 N   H   H   H   H   Me   359   0.964   61% @5   1.1               220   CO 2 Me   —NHPh   H   H   H   H   Me   345   0.084   1.8   0.637               241   CO 2 Me                             
C 8 H 9     H   H                             
C 4 H 6 NO 3     H   Me   473   0.0035   0.954   0.183               242   CO 2 Me                             
C 11 H 9     H   H                             
C 4 H 6 NP 3     H   Me   509   0.0038   0.782   0.141               243   CO 2 Me                             
C 4 H 9     H   H   H   H   Me   310   2.6               245   CO 2 Me                             
C 8 H 9     H   H                             
C 4 H 7 N 2 O 3     H   Me   488   0.0053   0.875   0.185               248   CO 2 Me                             
Cyclohexyl   H   H   H   H   Me   336   0.783   0.171   0.649               250   CO 2 Me                             
C 8 H 9     H   H                             
C 4 H 9 N 2 O 2     H   Me   474   0.0074   0.684   2.4               251   CO 2 Me                             
C 8 H 9     H   H                             
C 5 H 8 NO 3     H   Me   487   0.0054   0.754   0.26               253   CO 2 Me                             
C 5 H 10 N   H   H   H   H   Me   337   0.905   0.85   0.303               254   CO 2 Me                             
C 8 H 9     H   H                             
C 5 H 11 N 2 O 2     H   Me   488   0.0067   0.664   0.765               261   CO 2 Me                             
C 8 H 9     H   H                                 H   Me   500   0.0063   0.477   0.63               262   CO 2 Me                             
C 8 H 9     H   H                             
C 6 H 12 N 3 O   H   Me   499   0.008   0.702   3.7                  
 
         [0158]    
       
         
               
               
             
               
               
             
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                   
               
               
                   
                 Ia 
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
             
          
           
               
                   
                 Ki (nM) 
               
             
          
           
               
                   
                   
                   
                 A2a 
                   
               
               
                   
                   
                 A2a 
                 antago- 
                 A1 
               
               
                   
                 MS 
                 bind- 
                 nist 
                 bind- 
               
             
          
           
               
                 No. 
                 R 1   
                 R 2   
                 R 3a   
                 R 3b   
                 R 3c   
                 R 3d   
                 R 4   
                 (M + 1) 
                 ing 
                 function 
                 ing 
               
               
                   
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 14 
                 CO 2 Et c 6 h 4 BrO 2   
                 
                   
                             
                     
                         
                         
                     
                   
                 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 454 
                 451 
               
               
                   
               
               
                 22 
                 CO 2 Et 
                                           
C 7 H 5 O 2   
                 H 
                 H 
                 H 
                 H 
                 NH 2   
                 411 (M +23) 
                 70 
                 253 
               
               
                   
               
               
                 18 
                 CO 2 Me 
                                           
C 7 H 5 O 2   
                 H 
                 H 
                 H 
                 H 
                 Me 
                 374 
                 159 
                 &gt;1000 
                 584 
               
               
                   
               
               
                 27 
                 CO 2 Et 
                 Ph 
                 H 
                 H 
                 H 
                 H 
                 NH 2   
                 345 
                 42 
                 36 
                 554 
               
               
                   
               
               
                 23 
                 CO 2 Et 
                                           
C 7 H 5 O 2   
                 H 
                 H 
                 H 
                 H 
                 Me 
                 388 
                 251 
               
               
                   
               
               
                 275 
                 CO 2 Et 
                                           
C 7 H 4 BrO 2   
                 H 
                 H 
                 H 
                 H 
                 Me 
                 467 
                 263 
               
               
                   
               
               
                 41 
                 CO 2 Et 
                                           
C 4 H 3 O 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 334 
                 271 
               
               
                   
               
               
                 57 
                 CO 2 Et 
                                           
C 7 H 7   
                 H 
                 H 
                 H 
                 H 
                 Me 
                 358 
                 400 
               
               
                   
               
               
                 67 
                 CO 2 Me 
                                           
C 7 H 7   
                 H 
                 H 
                 H 
                 H 
                 Me 
                 344 
                 39 
                 128 
                 1853 
               
               
                   
               
               
                 66 
                 CO 2 Me 
                                           
C 7 H 7   
                 H 
                 H 
                 H 
                 H 
                 Me 
                 344 
                 46 
                 151 
                 1591 
               
               
                   
               
               
                 85 
                 CO 2 Me 
                                           
C 6 H 4 Br 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 431 (M +23) 
                 35 
                 &gt;1000 
                 5570 
               
               
                   
               
               
                 82 
                 CO 2 Me 
                                           
C 8 H 9   
                 H 
                 NH 2   
                 H 
                 H 
                 Me 
                 373 
                 294 
               
               
                   
               
               
                 95 
                 CO 2 Me 
                                           
C 11 H 9   
                 H 
                 H 
                 H 
                 H 
                 NH 2   
                 395 
                 286 
               
               
                   
               
               
                 135 
                 CO 2 Me 
                                           
C 5 H 4 N 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 331 
                 123 
               
               
                   
               
               
                 130 
                 CO 2 Me 
                                           
C 6 H 6 N 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 345 
                 222 
               
               
                   
               
               
                 141 
                 CO 2 Me 
                                           
C 6 H 5 O 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 346 
                 172 
               
               
                   
               
               
                 183 
                 CO 2 Et 
                                           
C 8 H 10 N 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 387 
                 191 
               
               
                   
               
               
                 208 
                 CO 2 Me 
                                           
C 7 H 4 N 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 355 
                 171 
               
               
                   
               
               
                 197 
                 CO 2 Et 
                                           
C 6 H 5 BrN 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 437 
                 148 
               
               
                   
               
               
                 217 
                 CO 2 Me 
                                           
C 7 H 6 F 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 362 
                 119 
               
               
                   
               
               
                 221 
                 CO 2 Me 
                                           
C 6 H 5 BrN 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 423 
                 76 
                 258 
                 2180 
               
               
                   
               
               
                 222 
                 CO 2 Me 
                 2-Pyridyl 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 353 (M +23) 
                 237 
               
               
                   
               
               
                 198 
                 CO 2 Et 
                                           
C 7 H 8 NO 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 389 
                 185 
               
               
                   
               
               
                 199 
                 CO 2 Et 
                                           
C 6 H 3 I 2 O 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 612 
                 301 
               
               
                   
               
               
                 279 
                 CO 2 Me 
                                           
C 8 H 9   
                 H 
                 
                   
                             
                     
                         
                         
                     
                   
                 
                 H 
                 H 
                 Me 
                 513 
                 179 
               
               
                   
               
               
                 261 
                 CO 2 Me 
                                           
C 8 H 9   
                 H 
                 H 
                                           
C 6 H 11 N 2 O 2   
                 H 
                 Me 
                 500 
                 472 
               
               
                   
               
               
                 280 
                 CO 2 Me 
                                           
C 8 H 9   
                 H 
                 
                   
                             
                     
                         
                         
                     
                   
                 
                 H 
                 H 
                 Me 
                 516 
                 237 
               
               
                   
               
               
                 276 
                 CO 2 Me 
                                           
C 8 H 9   
                 H 
                 H 
                                           
C 5 H 6 N 3 O 
                 H 
                 Me 
                 481 
                 304 
               
               
                   
               
               
                 258 
                 CO 2 Me 
                                           
C 8 H 9   
                 H 
                                           
C 6 H 11 N 2 O 2   
                 H 
                 H 
                 Me 
                 500 
                 211 
               
               
                   
               
               
                 281 
                 CO 2 Me 
                                           
C 8 H 9   
                 H 
                 
                   
                             
                     
                         
                         
                     
                   
                 
                 H 
                 H 
                 Me 
                 501 
                 201 
               
               
                   
               
               
                 262 
                 CO 2 Me 
                                           
C 8 H 9   
                 H 
                 H 
                                           
C 6 H 12 N 3 O 
                 H 
                 Me 
                 499 
                 332 
               
               
                   
               
               
                 184 
                 CO 2 Et 
                                           
C 7 H 8 N 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 373 
                 140 
               
               
                   
               
               
                 195 
                 CO 2 Et 
                                           
C 6 H 4 Cl 2 N 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 427 
                 171 
               
               
                   
               
               
                 260 
                 CO 2 Me 
                                           
C 8 H 9   
                 H 
                                           
C 5 H 6 N 3 O 
                 H 
                 H 
                 Me 
                 481 
                 163 
               
               
                   
               
               
                 263 
                 CO 2 Me 
                                           
C 8 H 9   
                 H 
                 H 
                                           
C 2 H 4 NO 2   
                 H 
                 Me 
                 431 
                 480 
               
               
                   
               
               
                 245 
                 CO 2 Me 
                                           
C 8 H 9   
                 H 
                 H 
                                           
C 4 H 7 N 2 O 3   
                 H 
                 Me 
                 488 
                 276 
               
               
                   
               
               
                 264 
                 CO 2 Me 
                                           
C 7 H 5 O 2   
                 H 
                 H 
                 H 
                 H 
                 NH 2   
                 397 (M +23) 
                 342 
               
               
                   
               
               
                 265 
                 CO 2 Me 
                 Ph 
                 H 
                 H 
                 H 
                 H 
                 NH 2   
                 353 (M +23) 
                 50 
               
               
                 267 
                 CO 2 Me 
                 2-Furyl 
                 H 
                 H 
                 H 
                 H 
                 NH 2   
                 321 
                 &lt;15 
               
               
                 268 
                 CO 2 Me 
                 3-Furyl 
                 H 
                 H 
                 H 
                 H 
                 NH 2   
                 321 
                 21 
               
               
                 269 
                 CO 2 Me 
                 H 
                 H 
                 H 
                 H 
                 Me 
                 320 
                 192 
               
               
                 270 
                 CO 2 Me 
                 2-Furyl 
                 H 
                 H 
                 H 
                 NH 2   
                 Me 
                 335 
                 303 
               
               
                 271 
                 CO 2 Me 
                 2-Furyl 
                 NH OH 
                 H 
                 H 
                 H 
                 Me 
                 351 
                 276 
               
               
                 272 
                 CO 2 Et 
                 2-Furyl 
                 H 
                 H 
                 H 
                 H 
                 NH 2   
                 335 
                 &lt;5 
               
               
                 273 
                 CO 2 Et 
                 2-Furyl 
                 H 
                 Br 
                 H 
                 H 
                 NH 2   
                 413 
                 279 
               
               
                 274 
                 CO 2 Et 
                 2-Furyl 
                 H 
                 H 
                 Br 
                 H 
                 NH 2   
                 413 
                 143