Patent Publication Number: US-5298619-A

Title: 1,4-dihydropyridine compounds with PAF-antagonistic activity

Description:
TECHNICAL FIELD OF THE INVENTION 
     The invention is related to a series of pharmaceutical compounds containing 1,4-dihydropyridines with an alkyl group at position 4 of the ring, which possess antagonistic activity of the Platelet Activating Factor (PAF-&#34;acether&#34;) and their methods or preparation. 
     BACKGROUND OF THE INVENTION 
     Some 1,4-dihydropyridines having an aliphatic group at position 4 of the ring, show a strong PAF-antagonistic activity not described until now (German Patent DE 3,801,717, 24th May 1989). 
     Surprisingly, the modulation of the side-chain at position 3 of the said ring has led to new molecules with antagonistic activity of the PAF receiver, having greater specificity, power and a much longer duration of the effect than those described in the aforementioned patent. 
     The chemical structure of the PAF-&#34;acether was identified as 1-O-hexadecyl/octodecyl-2-acetyl-sn-glycero-3-phosphocoline. This compound is a phospholipidic autacoid and a mediator of extremely potent inflammatory reactions liberated by several types of cell, human tissues and experiment animals. These cells are mainly basophile, eosinophile and neutrophile granulocytes, tissue macrophages and monocutes of the peripheral blood, platelets, glandular epithelium cells, endothelial cells and neuronic tissue. The PAF-&#34;acether&#34; is powerful inducer of the systemic aggregation and hypotension. This effect is due to its capacity of promoting the peripheral vasodilatation, but also influences its action over pulmonary circulation and the heart, since it produces diminution of the miocardic contractility and coronary flow. Another effect of the PAF-&#34;acether&#34; is that of inducing bronchoconstriction at doses 100 times lower than histamine. It has also been described that the PAF-&#34;acether&#34; and thus, PAF-&#34;acether&#34; antagonists directly and indirectly regulate the lymphocyte function. 
     Due to all these effects, the PAF has been described as the main mediator of immunological and inflammatory illnesses. 
     On this basis, specific inhibitors of biosynthesis and/or the effects of the PAF-&#34;acether&#34; could represent a new class of therapeutic agents, especially in pulmonary illnesses like bronchial asthma, allergic pneumonitis and adult respiratory distress, in which some PAF-&#34;acether&#34; antagonists have reduced or abolished anaphylactic reactions and hypersensitiveness, endotoxic shock and gastric ulcers. Also, the participation of the PAF-&#34;acether&#34; has been demonstrated in a series of pathologic states of an immunoallergic nature like inflammatory processes, psoriasis, glomerulonephritis and transplant rejection. 
     Some Ca++ antagonists also present PAF antagonistic properties, as is the case with Diltiazem and Gallopamil. However, not all the Ca++ channel blocking agents have this activity. So, the 1,4-dihydropyridines, like Nifedipina, only show a very weak activity, since the concentrations needed to obtain an effect are 1,000,000 higher than those inhibiting calcium flow in other cells and, at least, 1,000 times greater than the specific antagonists of the PAF-&#34;acether&#34;. 
     The invention, therefore, is referred to a series of new 1,4-dihydropyridines corresponding to formula (i) with antagonistic activity of the PAF-&#34;acether&#34;, to the pharmaceutical compositions that contain them and their methods of preparation: ##STR2## where: R is a saturated alkyl chain of C1-C2 like methyl or ethyl 
     R&#39; is a saturated or unsaturated alkyl chain of C1-C16, lineal, branched or cyclic, such as methyl, ethyl, isopropyl, tertiary-butyl, n-hexyl, n-hexadecyl, allyl, 1-undecenyl and cinnamyl. It can also be interrupted by an oxygen atom, like 2-methoxyethyl or tetrahydrofurfuryl and can also represent the 2-(N-morpholine) ethyl grouping 
     n is a number that can be 2 and 3 
     X defines an oxygen atom (O), or sulphur (S), or a SO2 grouping 
     Ar represents an aromatic ring such as phenyl except in those compounds having X=S and n=2. It also represents a substituted phenyl group such as 4-nitrophenyl, 4-acetylaminophenyl, 4-chlorophenyl, 3,4-dichlorophenyl, 4-methylphenyl, 4-methoxyphenyl, 3-dimethyl-aminophenyl, 4-biphenyl, 4-phenoxyphenyl, 4-benzylphenyl, 4-benzyloxyphenyl. It can also represent the 1-naphthyl and 2-naphthyl groups. 
     The pharmacological activity of compounds of formula (I) have been established as is indicated later on. 
     The compounds can be obtained using known methods already described in the literature: 
     METHOD A 
     A compound of formula (II) ##STR3## where R&#39; has been defined above, is made to react with a compound of formula (III) 
     
         H.sub.3 C--CO--CH.sub.2 --COO--(CH.sub.2).sub.n --X--Ar 
    
     where n, X and Ar have been previously defined, and an aldehyde of formula (IV) 
     
         R--CHO 
    
     where R has been defined above, giving a compound of formula (I) or 
     METHOD B 
     A compound of formula (V) 
     
         H.sub.3 C--CO--CH.sub.2 --COO--R&#39; 
    
     where R&#39; has been defined above, is made to react with a compound of formula (VI) ##STR4## where n, X and Ar have beet defined above, and an aldehyde of formula (IV), where R has already been defined, giving a compound of formula (I) or 
     METHOD C 
     A compound of formula (VII) ##STR5## where R and R&#39; have been defined above, is made to react with a compound of formula (VI), where n, X and Ar have been described above, giving a compound of formula (I) 
     The invention also refers to those process methods where one starts from a compound obtainable as an intermediate in any stage of the process and the remaining process stages are completed or the process is interrupted in any stage, or in which a starting product is prepared under the reaction conditions or in which a reactant is presented as its salts. 
     The mixtures of diastereoisomers or enantiomers obtained, can be separated thanks to the different physical chemical properties of the components, by means of known methods, like for example fractionated recrystallization and/or chromatography, by reactions of asymmetric induction or by the use of microorganisms. 
     The starting compounds are known or in the case of being new, they can be obtained following known methods. 
     The new compounds can be used as drugs to be administered orally, parenterally or rectally as a pharmaceutical preparation, containing one of the compounds of formula (I) in combination with an acceptable pharmaceutical excipient. The pharmaceutical preparations can be presented, for example, as tablets, pills, capsules, injectables, suppositories or in the liquid form as a syrup. Usually the amount of active compound is between 0.1 and 99% by weight of the preparation, preferable between 2 and 50% by weight in oral preparations. 
     The daily dose of the active substance depends on the type of administration. Generally, from 50-100 mg/day are administered orally. 
    
    
     PREPARATION METHODS OF THE INVENTION 
     The following examples illustrate the present invention without limiting it in any way. 
     EXAMPLE 1 (METHOD A) 
     Preparation of 3-(4-chlorophenylthio) propyl 5-methoxycarbonyl-2,4,6-trimethyl-1,4-dihydropyridine-3-carboxylate. 
     A solution composed of 9 g (0.03 mol) of 3-(4-chlorophenylthio) propyl acetylacetate, 3,56 g (0.03 mol) of methyl 3-aminocrotonate and 1.9 ml (1.49 g; 0.034 mol) of a acetaldehyde in 40 ml. of absolute ethanol, is refluxed with stirring for 7 hours. After the said time, the solvent is evaporated at reduced pressure and the residue obtained is dissolved in 15 ml of boiling ethyl acetate. The resulting solution is stirred at room temperature and afterwards it is cooled to -10° C. The solid obtained is recrystallized in methanol finally producing a yellow solid of Melting Point=99°-101° C. The yield of the reaction is 68%. 
     EXAMPLE 2 (METHOD A) 
     Preparation of 2-(4-methylphenylsulphonyl) ethyl 5-methoxycarbonyl-2,4,6-trimethyl-1,4-dihydropyridine-3-carboxylate. 
     A solution composed of 8.5 g (0.03 mol) of 2-(4-methylphenylsulphonyl) ethyl acetylacetate, 3.45 g (0.03 mol) of methyl 3-aminocrotonate and 1.67 ml (0.03 mol) of acetaldehyde in 30 ml of absolute ethanol, is heated to reflux with stirring during 8 hours. After said time, the solvent is evaporated at reduced pressure and the residue obtained is dissolved in 10 ml of boiling methanol. Lastly, the resulting solution is stirred at 0° C. and the solid obtained is recrystallized in methanol resulting in a white solid of Melting Point=96°-100° C. The yield of the reaction is 45%. 
     EXAMPLE 3 (METHOD A) 
     Preparation of 3-(4-phenylphenoxy) propyl 5-methoxycarbonyl-2,4,6-trimethyl-1,4-dihydropyridine-3-carboxylate. 
     A solution composed of 10.9 g (0.035 mol) of 3-(4-phenylphenoxy) propyl acetylacetate, 4 g (0.035 mol) of methyl 3-aminocrotonate and 1.95 ml (0.35 mol) of acetaldehyde in 35 ml of absolute ethanol is heated to reflux with stirring during 8 hours. After said time 20 ml of solvent is evaporated at reduced pressure and the resulting solution is left to cool at room temperature. In this way a solid is obtained which is recrystallized in acetonitrile, finally giving a white solid of Melting Point=133°-5° C. The yield of the reaction is 74%. 
     EXAMPLE 4 (METHOD A) 
     Preparation of 3-(4-methylphenylthio) propyl 5-methoxycarbonyl-2,4,6-trimethyl-1,4-dihydropyridine-3-carboxylate. 
     A solution composed of 9 g (0.034 mol) of 3-(4-methylphenylthio) propyl acetylacetate, 3.9 g (0.034 mol) of methyl 3-aminocrotonate and 2.26 ml (1.76 g; 0.040 mol) of acetaldehyde in 45 ml of absolute ethanol is heated to reflux with stirring during 7 hours. After said time, the solvent is evaporated at reduced pressure and the residue obtained is dissolved in 10 ml of boiling isopropyl ether. Afterwards, the resulting solution, is stirred at room temperature until the complete solidification of the product. Lastly, the solid so obtained is recrystallized in isopropyl ether resulting in a solid of Melting Point=80°-2° C. The yield of the reaction is 49%. 
     EXAMPLE 5 (METHOD A) 
     Preparation of 2-(phenylsulphonyl) ethyl 5-methoxycarbonyl-2,4,6-trimethyl-1,4-dihydropyridine-3-carboxylate. 
     A mixture composed of 30 g (0.11 mol) of 2-(phenylsulphonyl) ethyl acetylacetate, 12.78 g (0.11 mol) of methyl 3-aminocrotonate and 6.5 ml (5.07 g; 0.12 mol) of acetaldehyde in 110 ml of absolute ethanol is heated to reflux with stirring during 8 hours. After said time, the solvent is evaporated at reduced pressure and the residue obtained is dissolved in 25 ml of boiling diisopropyl ether. Afterwards, the resulting solution, is cooled to -10° C. overnight. In this way, a yellow solid is obtained which is recrystallized in n-hexane/ethyl acetate (1:1), finally resulting in a product of Melting Point=118°-20° C. with a yield of 75%. 
     EXAMPLES 6-151 (METHOD A) 
     The compounds of Table 1 were prepared in an analogous way to that indicated in the aforementioned examples 1-5. 
     
                                           TABLE 1                                 
__________________________________________________________________________
Example                         M.P..sup.a                                
                                       Yield.sup.b                        
No.  R  R&#39;        n x  Ar       (°C.)                              
                                       (%)                                
__________________________________________________________________________
 6   CH.sub.3                                                             
        CH.sub.3  3 O  Ph       97-100.sup.c                              
                                       45                                 
 7   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 O  Ph       11-3.sup.c                                
                                       76                                 
 8   CH.sub.3                                                             
        (CH.sub.3).sub.2 --CH                                             
                  3 O  Ph       120-2.sup.d                               
                                       65                                 
 9   CH.sub.3                                                             
        (CH.sub.3).sub.3 --C                                              
                  3 O  Ph       101-2.sup.e                               
                                       30                                 
10   CH.sub.3                                                             
        (CH.sub.3).sub.2 --CH                                             
                  3 S  Ph       77-9.sup.f                                
                                       35                                 
11   CH.sub.3                                                             
        CH.sub.2 ═CH--CH.sub.2                                        
                  3 O  Ph       69-72.sup.f                               
                                       40                                 
12   CH.sub.3                                                             
        CH.sub.2 ═CH--CH.sub.2                                        
                  3 S  Ph       aceite 69                                 
13   CH.sub.3                                                             
        CH.sub.3  3 SO.sub.2                                              
                       Ph       114-7.sup.d                               
                                       30                                 
14   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 SO.sub.2                                              
                       Ph       89-92.sup.g                               
                                       40                                 
15   CH.sub.3                                                             
        CH.sub.3  3 O  4-NO.sub.2 -Ph                                     
                                153-4.sup.d                               
                                       69                                 
16   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 O  4-NO.sub.2 -Ph                                     
                                133-5.sup.d                               
                                       70                                 
17   CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  3 O  4-NO.sub.2 -Ph                                     
                                113-5.sup.d                               
                                       64                                 
18   CH.sub.3                                                             
        CH.sub.3 --(CH.sub.2).sub.5                                       
                  3 O  4-NO.sub.2 -Ph                                     
                                84-5.sup.c                                
                                       35                                 
19   CH.sub.3                                                             
        M-(CH.sub.2).sub.2.sup.h                                          
                  3 O  4-NO.sub.2 -Ph                                     
                                125-30.sup.e                              
                                       57                                 
20   CH.sub.3                                                             
        CH.sub.3 --(CH.sub.2).sub.15                                      
                  3 O  4-NO.sub.2 -Ph                                     
                                104-6.sup.g                               
                                       38                                 
21   CH.sub.3                                                             
        (CH.sub.3).sub.3 C                                                
                  3 O  4-NO.sub.2 -Ph                                     
                                106-g.sup.f                               
                                       25                                 
22   CH.sub.3                                                             
        CH.sub.2 ═CH--CH.sub.2                                        
                  3 O  4-NO.sub.2 -Ph                                     
                                102-5.sup.d                               
                                       33                                 
23   CH.sub.3                                                             
        CH.sub.3  3 O  4-AcNH-Ph                                          
                                103-5.sup.c                               
                                       65                                 
24   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 O  4-AcNH-Ph                                          
                                142-5.sup.c                               
                                       40                                 
25   CH.sub.3                                                             
        (CH.sub.3).sub.2 --CH                                             
                  3 O  4-AcNH-Ph                                          
                                118-21.sup.c                              
                                       45                                 
26   CH.sub.3                                                             
        M--(CH.sub.2).sub.2                                               
                  3 O  4-AcNH-Ph                                          
                                135-8.sup.e                               
                                       35                                 
27   CH.sub.3                                                             
        CH.sub.3 --(CH.sub.2).sub.5                                       
                  3 O  4-AcNH-Ph                                          
                                55-9.sup.c                                
                                       24                                 
28   CH.sub.3                                                             
        (CH.sub.3).sub.3 C                                                
                  3 O  4-AcNH-Ph                                          
                                101-4.sup.c                               
                                       49                                 
29   CH.sub.3                                                             
        CH.sub.3 O--(CH.sub.2).sub.2                                      
                  3 O  4-AcNH-Ph                                          
                                75-80.sup.c                               
                                       24                                 
30   CH.sub.3                                                             
        CH.sub.3  3 S  4-AcNH-Ph                                          
                                72-4.sup.c                                
                                       26                                 
31   CH.sub.3                                                             
        CH.sub.3 --(CH.sub.2).sub.15                                      
                  3 S  4-AcNH-Ph                                          
                                85-7.sup.f                                
                                       60                                 
32   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 S  4-AcNH-Ph                                          
                                63-5.sup.i                                
                                       24                                 
33   CH.sub.3                                                             
        CH.sub.2 ═CH--CH.sub.2                                        
                  3 S  4-AcNH-Ph                                          
                                140-2.sup.c                               
                                       35                                 
34   CH.sub.3                                                             
        CH.sub.2 ═CH--CH.sub.2                                        
                  3 O  4-AcNH-Ph                                          
                                98-CO3.sup.d                              
                                       23                                 
35   CH.sub.3                                                             
        CH.sub.3  3 O  4-Cl-Ph  129-31.sup.c                              
                                       66                                 
36   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 O  4-Cl-Ph  135-8.sup.c                               
                                       46                                 
37   CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  3 O  4-Cl-Ph  108-11.sup.c                              
                                       65                                 
38   CH.sub.3                                                             
        (CH.sub.3).sub.3 C                                                
                  3 O  4-Cl-Ph  91-3.sup.f                                
                                       20                                 
39   CH.sub.3                                                             
        CH.sub.2 ═CH--CH.sub.2                                        
                  3 O  4-Cl-Ph  105-g.sup.f                               
                                       51                                 
40   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 O  3,4Cl.sub.2 -Ph                                    
                                134-6.sup.c                               
                                       60                                 
41   CH.sub.3                                                             
        CH.sub.3  3 O  3,4Cl.sub.2 -Ph                                    
                                82-4.sup.d                                
                                       31                                 
42   CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  3 O  3,4Cl.sub.2 -Ph                                    
                                130-3.sup.d                               
                                       55                                 
43   CH.sub.3                                                             
        (CH.sub.3).sub.3 C                                                
                  3 O  3,4Cl.sub.2 -Ph                                    
                                110-2.sup.i                               
                                       39                                 
44   CH.sub.3                                                             
        CH.sub.2 ═CH--CH.sub.2                                        
                  3 O  3,4Cl.sub.2 -Ph                                    
                                99-101.sup.c                              
                                       60                                 
45   CH.sub.3                                                             
        CH.sub.3  3 S  3,4Cl.sub.2 -Ph                                    
                                104-6.sup.c                               
                                       35                                 
46   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 S  3,4Cl.sub.2 -Ph                                    
                                63-6.sup.f                                
                                       24                                 
47   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 O  4-CH.sub.3 -Ph                                     
                                109-11.sup.c                              
                                       45                                 
48   CH.sub.3                                                             
        CH.sub.3  3 O  4-CH.sub.3 -Ph                                     
                                117-9.sup.d                               
                                       50                                 
49   CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  3 O  4-CH.sub.3 -Ph                                     
                                121-3.sup.c                               
                                       60                                 
50   CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  3 O  4-CH.sub.3 -Ph                                     
                                109-11.sup.f                              
                                       44                                 
51   CH.sub.3                                                             
        CH.sub.2 ═CH--CH.sub.2                                        
                  3 O  4-CH.sub.3 -Ph                                     
                                80-3.sup.f                                
                                       22                                 
52   CH.sub.3                                                             
        CH.sub.3  3 SO.sub.2                                              
                       4-CH.sub.3 -Ph                                     
                                137-9.sup.c                               
                                       40                                 
53   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 SO.sub.2                                              
                       4-CH.sub.3 -Ph                                     
                                139-41.sup.d                              
                                       18                                 
54   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 SO.sub.2                                              
                       4-CH.sub.3 -Ph                                     
                                85-8.sup.d                                
                                       38                                 
55   CH.sub.3                                                             
        CH.sub.3  3 O  2-Naphthyl                                         
                                118-21.sup.e                              
                                       33                                 
56   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 O  2-Naphthyl                                         
                                98-100.sup.c                              
                                       30                                 
57   CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  3 O  2-Naphthyl                                         
                                100-3.sup.d                               
                                       25                                 
58   CH.sub.3                                                             
        (CH.sub.3).sub.3 C                                                
                  3 O  2-Naphthyl                                         
                                87-9.sup.f                                
                                       22                                 
59   CH.sub.3                                                             
        CH.sub.2 ═CH--CH.sub.2                                        
                  3 O  2-Naphthyl                                         
                                88-90.sup.d                               
                                       20                                 
60   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 O  4-CH.sub.3 O-Ph                                    
                                125-7.sup.d                               
                                       70                                 
61   CH.sub.3                                                             
        CH.sub.3  3 O  4-CH.sub.3 O-Ph                                    
                                80-3.sup.c                                
                                       31                                 
62   CH.sub.3                                                             
        CH.sub.3  2 O  4-Ch.sub.3 O-Ph                                    
                                107-9.sup.d                               
                                       60                                 
63   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 O  4-CH.sub.3 O-Ph                                    
                                64-6.sup.f                                
                                       32                                 
64   CH.sub.3                                                             
        CH.sub.3  2 O  4-Ph-Ph  84-6.sup.j                                
                                       40                                 
65   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 O  4-Ph-Ph  115-7.sup.d                               
                                       25                                 
66   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 O  4-Ph-Ph  135-7.sup.d                               
                                       81                                 
67   CH.sub.3                                                             
        CH.sub.3  3 O  4-(Ph-CH.sub.2)-Ph                                 
                                93-6.sup.c                                
                                       15                                 
68   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 O  4-(Ph-CH.sub.2)-Ph                                 
                                93-5.sup.e                                
                                       15                                 
69   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 O  4-(Ph-CH.sub.2)-Ph                                 
                                111-4.sup.c                               
                                       30                                 
70   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 O  4-(Ph-CH.sub.2 O)-Ph                               
                                78-81.sup.d                               
                                       22                                 
71   CH.sub.3                                                             
        CH.sub.3  2 O  4-(Ph-CH.sub.2 O)-Ph                               
                                121-3.sup.k                               
                                       15                                 
72   CH.sub.3                                                             
        CH.sub.3  3 O  4-(Ph-CH.sub.2 O)-Ph                               
                                107-9.sup.d                               
                                       40                                 
73   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 O  4-(Ph-CH.sub.2 O)-Ph                               
                                109-11.sup.f                              
                                       20                                 
74   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 SO.sub.2                                              
                       Ph       90-3   88                                 
75   CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  2 SO.sub.2                                              
                       Ph       86-9   46                                 
76   CH.sub.3                                                             
        CH.sub.3  3 S  4-NO.sub.2 -Ph                                     
                                118-20.sup.c                              
                                       76                                 
77   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 S  4-NO.sub.2 -Ph                                     
                                84-8.sup.c                                
                                       47                                 
78   CH.sub.3                                                             
        (CH.sub.3).sub.3 C                                                
                  3 S  4-NO.sub.2 -Ph                                     
                                104-6.sup.f                               
                                       39                                 
79   CH.sub.3                                                             
        CH.sub.3 O--(CH.sub.2).sub.2                                      
                  3 S  4-NO.sub.2 -Ph                                     
                                65-8   89                                 
80   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 S  4-(AcNH)-Ph                                        
                                135-7.sup.i                               
                                       29                                 
81   CH.sub.3                                                             
        (CH.sub.3)2CH                                                     
                  2 S  4-(AcNH)-Ph                                        
                                110-2.sup.i                               
                                       37                                 
82   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 S  4-Cl-Ph  115-7.sup.d                               
                                       86                                 
83   CH.sub.3                                                             
        (CH.sub.3).sub.2 --CH                                             
                  3 S  4-Cl-Ph  79-81.sup.i                               
                                       29                                 
84   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 O  3,4Cl.sub.2 -Ph                                    
                                137-9.sup.c                               
                                       90                                 
85   CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  2 O  3,4Cl.sub.2 -Ph                                    
                                134-6.sup.c                               
                                       78                                 
86   CH.sub.3                                                             
        CH.sub.3  2 O  3,4Cl.sub.2 -Ph                                    
                                145-7.sup.c                               
                                       82                                 
87   CH.sub.3                                                             
        CH.sub.3 O--(CH.sub.2).sub.2                                      
                  2 O  3,4Cl.sub.2 -Ph                                    
                                110-2.sup.d                               
                                       70                                 
88   CH.sub.3                                                             
        CH.sub.3 --(CH.sub.2).sub.5                                       
                  2 O  3,4Cl.sub.2 -Ph                                    
                                106-8.sup.c                               
                                       65                                 
89   CH.sub.3                                                             
        (CH.sub.3).sub.3 C                                                
                  2 O  3,4Cl.sub.2 -Ph                                    
                                157-9.sup.c                               
                                       90                                 
90   CH.sub.3                                                             
        M--(CH.sub.2).sup.h.sub.2h                                        
                  2 O  3,4Cl.sub.2 -Ph                                    
                                106-9.sup.c                               
                                       75                                 
91   CH.sub.3                                                             
        THF-CH.sub. 2                                                     
                  2 O  3,4Cl.sub.2 -Ph                                    
                                134-6.sup.d                               
                                       47                                 
92   CH.sub.3                                                             
        CH.sub.3 -- (CH.sub.2).sub.15                                     
                  2 O  3,4Cl.sub.2 -Ph                                    
                                88-90.sup.d                               
                                       45                                 
93   CH.sub.3                                                             
        CH.sub.2 ═CH--CH.sub.2                                        
                  2 O  3,4Cl.sub.2 -Ph                                    
                                120-2.sup.c                               
                                       81                                 
94   CH.sub.3                                                             
        CH.sub.2 ═CH--(CH.sub.2).sub.9                                
                  2 O  3,4Cl.sub.2 -Ph                                    
                                86-7.sup.d                                
                                       70                                 
95   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 S  4CH.sub.3 -Ph                                      
                                68-71  57                                 
96   CH.sub.3                                                             
        M-(CH.sub. 2).sub.2                                               
                  3 S  4CH.sub.3 -Ph                                      
                                175-9dese.sup.ll                          
                                       32                                 
                                hydrochloride                             
97   CH.sub.3                                                             
        CH.sub.3  2 O  2-Naphthyl                                         
                                115-7.sup.c                               
                                       63                                 
98   CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 O  2-Naphthyl                                         
                                141-3.sup.c                               
                                       67                                 
99   CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  2 O  2-Naphthyl                                         
                                130-2.sup.d                               
                                       43                                 
100  CH.sub.3                                                             
        CH.sub.3 O--(CH.sub.2).sub.2                                      
                  2 O  2-Naphthyl                                         
                                103-5.sup.c                               
                                       53                                 
101  CH.sub.3                                                             
        CH.sub.3 --(CH.sub.2).sub.5.sbsb.h                                
                  2 O  2-Naphthyl                                         
                                87-9.sup.c                                
                                       70                                 
102  CH.sub.3                                                             
        THF-CH.sub. 2                                                     
                  2 O  2-Naphthyl                                         
                                102-4  47                                 
103  CH.sub.3                                                             
        CH.sub.2 ═CH--CH.sub.2                                        
                  2 O  2-Naphthyl                                         
                                141-3.sup.d                               
                                       78                                 
104  CH.sub.3                                                             
        M-(CH.sub. 2).sub.2.sup.h                                         
                  2 O  2-Naphthyl                                         
                                96-9   77                                 
105  CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 O  Ph       91-3,5.sup.d                              
                                       26                                 
106  CH.sub.3                                                             
        CH.sub.3  3 S  4-CH.sub.3 O-Ph                                    
                                83-4.sup.f                                
                                       25                                 
107  CH.sub.3                                                             
        CH.sub.3  2 O  Ph       103-5.sup.d                               
                                       68                                 
108  CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  2 O  Ph       95-7.sup.m                                
                                       78                                 
109  CH.sub.3                                                             
        CH.sub.3  2 O  4-(Ph-CH.sub.2)-Ph                                 
                                132-3.sup.g                               
                                       25                                 
110  CH.sub.3                                                             
        CH.sub.3  2 O  4-NO.sub.2 Ph                                      
                                185-7.sup.d                               
                                       66                                 
111  CH.sub.3                                                             
        (CH.sub.3).sub.3 C                                                
                  2 O  4-NO.sub.2 -Ph                                     
                                170-3.sup.d                               
                                       80                                 
112  CH.sub.3                                                             
        (CH.sub.3).sub.3 C                                                
                  2 O  2-Naphthyl                                         
                                101-3.sup.f                               
                                       24                                 
113  CH.sub.3                                                             
        CH.sub.3  2 O  1-Naphthyl                                         
                                134-7.sup.c                               
                                       75                                 
114  CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 O  1-Naphthyl                                         
                                125-7.sup.c                               
                                       64                                 
115  CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  2 O  1-Naphthyl                                         
                                129-31.sup.j                              
                                       51                                 
116  CH.sub.3                                                             
        CH.sub.3 O--(CH.sub.2).sub.2                                      
                  2 O  1-Naphthyl                                         
                                105-7.sup. n                              
                                       26                                 
117  CH.sub.3                                                             
        CH.sub.3 --(CH.sub.2).sub.5                                       
                  2 O  1-Naphthyl                                         
                                106-8.sup.c                               
                                       55                                 
118  CH.sub.3                                                             
        M-(CH.sub.2).sub.2.sup.h                                          
                  2 O  1-Naphthyl                                         
                                133-5.sup.c                               
                                       77                                 
119  CH.sub.3                                                             
        CH.sub.3 O--(CH.sub.2).sub.2                                      
                  2 O  4-NO.sub.2 -Ph                                     
                                130-2.sup.d                               
                                       68                                 
120  CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 O  4-NO.sub.2 -Ph                                     
                                162-3.sup.d                               
                                       69                                 
121  CH.sub.3                                                             
        (CH.sub.3)2CH                                                     
                  2 O  4-NO.sub.2 -Ph                                     
                                150-2.sup.d                               
                                       82                                 
122  CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 O  4-Cl-Ph  137-9.sup.c                               
                                       70                                 
123  CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  2 O  4-Cl-Ph  139-42.sup.d                              
                                       75                                 
124  CH.sub.3                                                             
        CH.sub.2 ═CH--CH.sub.2                                        
                  2 O  4-Cl-Ph  118-20.sup.ll                             
                                       24                                 
125  CH.sub.3                                                             
        CH.sub.3 O--(CH.sub.2).sub.2                                      
                  2 O  4-Cl-Ph  91-4.sup.c                                
                                       26                                 
126  CH.sub.3                                                             
        (CH.sub.3).sub.3 C                                                
                  2 O  4-Cl-Ph  111-4.sup.d                               
                                       50                                 
127  CH.sub.3                                                             
        CH.sub.3  2 O  4-Cl-Ph  142-5.sup.d                               
                                       74                                 
128  CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 O  4-CH.sub.3 -Ph                                     
                                115-7.sub.c                               
                                       59                                 
129  CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  2 O  4-Cl-Ph  83-5.sup.f                                
                                       68                                 
130  CH.sub.3                                                             
        CH.sub.3 O--(CH.sub.2).sub.2                                      
                  2 O  4-Cl-Ph  69-71.sup.f                               
                                       59                                 
131  CH.sub.3                                                             
        CH.sub.3  2 O  4-Cl-Ph  49-51.sup.f                               
                                       40                                 
132  CH.sub.3                                                             
        CH.sub.3 --(CH.sub.2).sub.15                                      
                  2 O  2-Naphthyl                                         
                                80-3.sup.d                                
                                       30                                 
133  CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 O  3-N(CH.sub.3).sub.2 -Ph                            
                                96-9.sup.i                                
                                       55                                 
134  CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 O  3-N(CH.sub.3).sub.2 -Ph                            
                                130-2.sup.d                               
                                       50                                 
135  CH.sub.3                                                             
        CH.sub.3  2 O  3-N(CH.sub.3).sub.2 -Ph                            
                                98-101.sup.d                              
                                       15                                 
136  CH.sub.3                                                             
        CH.sub.3 O--(CH.sub.2).sub.2                                      
                  2 O  3-N(CH.sub.3).sub.2 -Ph                            
                                112-4.sup.d                               
                                       44                                 
137  CH.sub.3                                                             
        (CH.sub.3).sub.3 C                                                
                  2 O  3-N(CH.sub.3).sub.2 -Ph                            
                                100-4.sup.d                               
                                       25                                 
138  CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  2 O  3-N(CH.sub.3).sub.2 -Ph                            
                                121-2.sup.d                               
                                       15                                 
139  CH.sub.3                                                             
        CH.sub.3  3 O  4-PhO-Ph 113-6.sup.c                               
                                       70                                 
140  CH.sub.3                                                             
        CH.sub.3  2 O  4-PhO-Ph 75-8.sup.f                                
                                       35                                 
141  CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  3 O  4-PhO-Ph 98-101.sup.c                              
                                       80                                 
142  CH.sub.3                                                             
        (CH.sub.3).sub.3 C                                                
                  3 O  4-PhO-Ph 89-91  55                                 
143  CH.sub.3                                                             
        CH.sub.3 --CH.sub.2                                               
                  2 O  4-PhO-Ph 96-8.sup.d                                
                                       77                                 
144  CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  2 O  4-PhO-Ph 93-6.sup.d                                
                                       75                                 
145  CH.sub.3                                                             
        CH.sub.3 O--(CH.sub.2).sub.2                                      
                  2 O  4-PhO-Ph 88-91.sup.c                               
                                       20                                 
146  CH.sub.3                                                             
        (CH.sub.3).sub.2 CH                                               
                  3 O  4-PhO-Ph 121-4.sup.c                               
                                       61                                 
147  CH.sub.3                                                             
        CH.sub.3  3 SO.sub.2                                              
                       4-NO.sub.2 -Ph                                     
                                191-3.sup.c                               
                                       25                                 
148  CH.sub.3                                                             
        CH.sub.3  3 SO.sub.2                                              
                       4-NO.sub.2 -Ph                                     
                                144-6.sup.d                               
                                       46                                 
149  CH.sub.3                                                             
        CH.sub.3  3 SO.sub.2                                              
                       3,4-Cl.sub.2 -Ph                                   
                                169-71.sup.d                              
                                       50                                 
150  CH.sub.3                                                             
        CH.sub.3  3 SO.sub.2                                              
                       4-CH.sub.3 O-Ph                                    
                                140-1.sup.c                               
                                       25                                 
151  CH.sub.3                                                             
        CH.sub.3  3 O  4-Ph-Ph  144-6.sup.c                               
                                       30                                 
__________________________________________________________________________
 .sup.a = Recrystallization solvent;                                      
 .sup.c = methanol;                                                       
  .sup.d = ethanol;                                                       
 .sup.e = isopropanol;                                                    
 .sup.f = diisopropylether;                                               
 .sup.g = ethyl acetate;                                                  
 .sup.1 = acetonitrile;                                                   
 .sup.j = nhexane/ethyl acetate (1:1);                                    
 .sup.ll = ethyl acetate/ethanol (1:1);                                   
 .sup.m = ethanol/water (2.5:1);                                          
 .sup.n = nhexane/ethyl acetate (2:1).                                    
 .sup.k = purification by MPLC                                            
 .sup.b = referred to the recrystallized product                          
 k = KEYS:                                                                
 M = NMorpholine;                                                         
 THF = 2Tetrahydrofurfuryl.                                               
 
    
     EXAMPLE 152 (METHOD B) 
     Preparation of 3-(2-naphthyloxy) propyl 5-ethoxycarbonyl-2,4,6-trimethyl-1,4-dihydropyridine-3-carboxylate. 
     A solution composed of 8-5 g (0.03 mol) of 3-(2-naphthyloxy) propyl 3-aminocrotonate, 3.82 ml (0.03 mol) of ethyl acetylacetate and 1.67 ml (0.03 mol) of acetaldehyde in 30 ml of absolute ethanol, is heated to reflux with stirring during 8 hours. After said time, 15 ml of solvent is evaporated at reduced pressure and the resulting mixture is stirred at 0° C., obtaining a white solid of Melting Point=94°-7° C. (recrystallized in ethanol). The yield of the reaction is 40%. 
     EXAMPLE 153 (METHOD B) 
     Preparation of 3-(4-nitrophenylthio) propyl 5-isopropoxycarbonyl-2,4,6-trimethil-1,4-dihydropyridine-3-carboxylate. 
     A solution composed of 9 g (0.03 mol) of 3-(4-nitrophenylthio) propyl 3-aminocrotonate, 5.04 g (0.03 mol) of isopropyl acetylacetate and 2.1 ml (1.58 g; 0.036 mol) of acetaldehyde in 45 ml of absolute ethanol, is heated to reflux with stirring during 7 hours. After said time, the solvent is evaporated at reduced pressure and the residue is dissolved in 16 ml of boiling ethyl acetate/n-hexane (1:1). Lastly, the resulting mixture is cooled to -10° C., obtaining a solid of Melting Point=80°-2° C. The yield of the reaction is 42%. 
     EXAMPLES 154-162 (METHOD B) 
     The compounds of Table 2 were obtained in an analogous way to that indicated in examples 152 and 153. 
     
                                           TABLE 2                                 
__________________________________________________________________________
Ex.                            M.P..sup.a                                 
                                   Yield.sup.b                            
no  R   R.sup.&#39;    n  x  Ar    (°C.)                               
                                   (%)                                    
__________________________________________________________________________
154 CH.sub.3                                                              
        CH.sub.3   3  O  1-Naphthyl                                       
                               40-3.sup.d                                 
                                   50                                     
155 CH.sub.3                                                              
        CH.sub.2 ═CH--CH.sub.2                                        
                   3  O  1-Naphythyl                                      
                               96-101.sup.c                               
                                   19                                     
156 CH.sub.3                                                              
        (CH.sub.3).sub.3 C                                                
                   3  S  Ph    Oil 74                                     
157 CH.sub.3                                                              
        CH.sub.3 --(CH.sub.2).sub.5                                       
                   3  S  4-NO.sub.2 -Ph                                   
                               74-7.sup.j                                 
                                   76                                     
158 CH.sub.3                                                              
        CH.sub.2 ═CH--CH.sub.2                                        
                   3  S  4-Cl-Ph                                          
                               55-7                                       
                                   68                                     
159 CH.sub.3                                                              
        Ph-CH═CH--CH.sub.2                                            
                   3  S  4-Cl-Ph                                          
                               117-20.sup.c                               
                                   87                                     
160 CH.sub.3                                                              
        CH.sub.2 ═CH--CH.sub.2                                        
                   3  S  4-CH.sub.3 -Ph                                   
                               58-60                                      
                                   64                                     
161 CH.sub.3                                                              
        Ph-CH═ CH--CH.sub.2                                           
                   3  S  4-CH.sub.3 -Ph                                   
                               84-7.sup.c                                 
                                   85                                     
162 CH.sub.3                                                              
        Ph-CH═ CH--CH.sub.2                                           
                   2  O  2-Naphthyl                                       
                               122-4.sup.c                                
                                   68                                     
__________________________________________________________________________
 .sup.a = Recrystallization solvent;                                      
 .sup.b = Referred to the recrystallized product;                         
 .sup.c = methanol;                                                       
 .sup.d = ethanol;                                                        
 .sup.j =  nhexane/ethyl acetate (1:1).                                   
 
    
     EXAMPLE 163 (METHOD C) 
     Preparation of 3-(phenylthio) propyl 5-methoxycarbonyl-2,4,6-trimethyl-1,4-dihydropyridine-3-carboxylate. 
     A solution composed of 5 g (0.035 mol) of methyl 2-acetyl-2-butenoate and 8.8 g (0.035 mol) of 3-(phenylthio) propyl 3-aminocrotonate in 35 ml of absolute ethanol, is heated to reflux with stirring during 10 hours. After said time, the solvent is evaporated at reduced pressure and the residue obtained is dissolved in 10 ml of boiling n-hexane/ethyl acetate (1:1). Lastly, the resulting solution is cooled to -10° C., obtaining a white solid of Melting Point=81°-2° C. (recrystallized in n-hexane/ethyl acetate (1:1)), with a yield of 45%. 
     EXAMPLE 164 (METHOD C) 
     Preparation of 3-(4-chlorophenylthio) propyl 2,6-dimethyl-4-ethyl-5-methoxycarbonyl-1,4-dihydropyridine-3-carboxylate. 
     A solution composed of 9 g (0-03 mol) of 3-(4-chlorophenylthio) propyl 3 -aminocrotonate and 4.95 g (0.031 mol) of methyl 2-acetyl-2-pentenoate in 45 ml of absolute ethanol, is heated to reflux with stirring during 7 hours. After said time, the reaction mixture is cooled to -10° ° C., crystallizing a solid of Melting Point=102°-4° C. (recrystallized in ethanol). The yield of the reaction is 50%. 
     EXAMPLE 165 (METHOD C) 
     Preparation of 3-(4-chlorophenylthio) propyl 2,6-dimethyl-4-ethyl-5-ethoxycarbonyl-1,4-dihydropyridine-3-carboxylate. 
     A mixture composed of 9 g (0.031 mol) of 3-(4-chlorophenylthio) propyl 3-aminocrotonate and 5.4 g (0.031 mol) of ethyl acetyl-2-pentenoate in 45 ml of absolute ethanol, is heated to reflux with stirring during 7 hours. After said time, the solvent is evaporated at reduced pressure and the residue obtained is dissolved in 10 ml of boiling diisopropylether. In continuation, the solution so obtained is stirred at room temperature until the complete solidification of the product. In this way a solid is obtained of Melting Point=83°-6° C. (recrystallized from diisopropylether), with a yield of 69%. 
     EXAMPLES 166-172 (METHOD C) 
     The compounds of Table 3 were obtained in analogous way to that indicated in examples 163-165. 
     
                                           TABLE 3                                 
__________________________________________________________________________
Ex.                          M.P..sup.a                                   
                                  Yield.sup.b                             
no  R      R.sup.&#39;                                                        
                 n  x  Ar    (°C.)                                 
                                  (%)                                     
__________________________________________________________________________
166 CH.sub.3                                                              
           CH.sub.3 --CH.sub.2                                            
                 3  S  Ph    84-5.sup.f                                   
                                  36                                      
167 CH.sub.3                                                              
           CH.sub.3                                                       
                 3  S  2-Naphthyl                                         
                             82-6.sup.j                                   
                                  50                                      
168 CH.sub.3                                                              
           CH.sub.3 --CH.sub.2                                            
                 3  S  2-Naphthyl                                         
                             62-5.sup.f                                   
                                  35                                      
169 CH.sub.3                                                              
           (CH.sub.3).sub.3 C                                             
                 3  S  4-Cl-Ph                                            
                             oil  35                                      
170 CH.sub.3                                                              
           (CH.sub.3).sub.3 C                                             
                 3  S  4-CH.sub.3 -Ph                                     
                             oil  35                                      
171 CH.sub.3 --CH.sub.2                                                   
           CH.sub.3 --CH.sub.2                                            
                 3  S  4-CH.sub.3 -Ph                                     
                             78-81.sup.f                                  
                                  73                                      
172 CH.sub.3 --CH.sub.2                                                   
           CH.sub.3                                                       
                 3  S  4-CH.sub.3 -Ph                                     
                             86-8.sup.f                                   
                                  52                                      
__________________________________________________________________________
 .sup.a = Recrystallization solvent;                                      
 .sup.b = Referred to the recrystallized product;                         
 .sup.f = diisopropylether;                                               
 .sup.j = nhexane/ethyl acetate (1:1).                                    
 
    
     PHARMACOLOGICAL STUDIES 
     STUDIES WITH WASHED PLATELETS: Aggregation 
     The suspensions of washed platelets were obtained from rabbit&#39;s blood (male, albino, New Zealand), anticoagulated with a solution of citric acid citrate/sodium dextrose in the ratio 1:6 (v:v). 
     The platelet rich plasma (PRP) was obtained by centrifuging blood samples at 100×g for 10 minutes and the platelets by centrifuging the PRP at 1,800×g for 15 minutes at 4° C. The pellet obtained in this way was washed twice with Tyrode tampon containing citric acid, PGE and aspirase, pH 6.5. The platelets so-washed were finally resuspended in Hepes-Tyrode tampon, pH 7.35 supplemented with bovine seric albumin at 0.35%; Ca++ 2 mM. 
     The final platelet concentration was adjusted to 300,000 platelets/mic-1. The aggregation was measured turbidimetrically using a lumiaggregometre (Chrono-Log.Co; Haventon, Pa., USA) at 37° C. under stirring at 1,100 r.p.m. The study was made in aliquots of preincubated PRP, with the compounds under study, for 5 minutes. The concentration of the antagonists was, in all cases, between 10 micM and 0.1 micM. The aggregation was induced by adding L-PAF diluted in 5 micl of Hepes/albumin tampon, the final concentration being 1.9×0,000000001. The IC50 for each compound was evaluated graphically from the dose-response curves. 
     
                       TABLE 1                                                     
______________________________________                                    
Effect on the aggregation induced by 1-PAF in rabbit                      
platelets.                                                                
Compound                                                                  
according to                                                              
example        IC.sub.50 (μM)                                          
______________________________________                                    
 1             0.34                                                       
 2             1.1                                                        
 3             0.24                                                       
 4             0.85                                                       
 5             1.3                                                        
 6             3.0                                                        
13             2.3                                                        
30             3.1                                                        
41             2.7                                                        
45             0.15                                                       
46             1.40                                                       
48             4.0                                                        
52             2.7                                                        
61             2.0                                                        
62             10.0                                                       
64             2.8                                                        
66             2.4                                                        
74             2.8                                                        
76             2.8                                                        
82             2.8                                                        
110            4.3                                                        
113            3.0                                                        
131            10.0                                                       
133            2.4                                                        
135            2.8                                                        
139            0.70                                                       
140            2.0                                                        
152            3.0                                                        
154            1.1                                                        
163            0.41                                                       
164            0.32                                                       
165            2.5                                                        
166            2.6                                                        
167            0.40                                                       
172            0.19                                                       
______________________________________                                    
 
    
     The data reflected is the mean of three experiments performed in duplicate. Concentration of 1-PAF=1.92 nM. 
     The concentrations of compounds, in all cases, were between 10 and 0.1 micM.