bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of 1,2:5,6‐Di‐O‐isopropylidene‐3‐O‐[3‐(uracil‐1‐yl)propionoyl]‐α‐D‐glucofuranose and 1,2‐Mono‐O‐isopropylidene‐6‐O‐[3‐(uracil‐1‐yl)propionoyl]‐α‐D‐glucofuranose
Authors: Ouchi Tatsuro , Jokei Satoshi , Chikashita Hidenori 
Published: March 2009

Abstract1,2:5,6‐Di‐O‐isopropylidene‐3‐O‐[3‐(uracil‐1‐yl)propionoyl]‐α‐D‐glucofuranose and 1,2‐mono‐O‐isopropylidene‐6‐O‐[3‐(uracil‐1‐yl)propionoyl]‐α‐D‐glucofuranose were synthesized.
Reaction of sulfene with heterocyclic N,N‐disubstituted α‐aminomethyleneketones. XI. Synthesis of 1,2‐oxathiino[5,6‐d]‐1‐benzoxepin derivatives
Authors: Menozzi Giulia , Mosti Luisa , Schenone Pietro , Cafaggi Sergio 
Published: March 2009

AbstractThe 1,4‐cycloaddition of sulfene to N,N‐disubstituted (E)‐4‐aminomethylene‐3,4‐dihydro‐1‐benzoxepin‐5(2H)‐ones gave, generally in excellent yield, N,N‐disubstituted 4‐amino‐3,4,5,6‐tetrahydro‐1,2‐oxathiino‐[5,6‐d)‐1‐benzoxepin 2,2‐dioxides, which are derivatives of the new heterocyclic system 1,2‐oxathiino[5,6‐d]‐1‐benzoxepin. This reaction did not occur only with the N,N‐diphenylenaminone.
Synthesis and some reactions of naphth[1,2‐d]oxazole‐5‐sulfonic acids
Authors: Osman A. M. , Youssef M. S. K. , Atta F. M. 
Published: March 2009

AbstractNaphth[1,2‐d]oxazole‐5‐sulfonic acid (1) has been prepared by the fusion of 4‐amino‐3‐hydroxynaphthalene‐1‐sulfonic acid with formamide. Interaction of 1 with a number of arenesulfonyl chlorides, aryloxyacetyl chlorides, 1‐naphthyloxyacetyl chloride, and chloroacetyl chloride gave 2‐(arylsulfonyl)‐, 2‐(aryloxyacetyl)‐, 2‐(1‐naphthyloxyacetyl)‐ and 2‐(chloroacetyl)naphth[1,2‐d]oxaxole‐5‐sulfonic acids (2, 3, 4 and 5), respectively. The corresponding sulfonyl chloride of 2 was condensed with amines giving the expected 2‐(arylsulfonyl)‐naphth[1,2‐d]oxazole‐5‐sulfonamides (6). Interaction of 5 with hydrazine gave 2‐hydrazinoacetyl and disubstituted hydrazine derivatives 7 and 8. Condensation of 7 with aromatic aldehydes yielded substituted hydrazonoacetyl derivatives 9. Two moles of 5 react with one mole of hydroquinone in dry acetone in the presence of anhydrous potassium carbonate and potassium iodide gave 1,4‐bis[5‐sulfonaphth[1,2‐d]oxazol‐2‐ylcarbonyl‐methoxy]benzene (10).
An alternative synthesis of tiopinac
Authors: Thurber T. Craig , Prince Anthony , Halpern Otto 
Published: March 2009

AbstractTiopinac (1) [6, 11‐dihydro‐11‐oxodibenzo[b,e]thiepin‐3‐acetic acid, (1)] has shown a high degree of antiinflammatory activity and a low incidence of side effects in animals (2). On the basis of these results, Tiopinac was chosen for human evaluation in 1978 (2a).
Preparation of monohalopyrroles
Authors: Aiello Enrico , Dattolo Gaetano , Cirrincione Girolamo , Almerico Anna Maria , D'Asdia Isabella 
Published: March 2009

AbstractMonobromo‐, monochloro‐ and monoiodopyrroles are obtained in excellent yields by using N‐halosuccinimides in dimethylformamide as halogenating agents.
Pyrido[1′,2′:1,2]pyrimido[5,4‐d]indoles. A new heterocyclic ring system
Authors: Unangst Paul C. 
Published: March 2009

AbstractThe preparation of the novel pyrido[1′,2′:1,2]pyrimido[5,4‐b]indole ring system is described ‐via fusion at 180° of ethyl 3‐amino‐1H‐indole‐2‐carboxylate 8a and several 6‐chloronicotinic acid derivatives. Similar fusion of 8a and thiourea yielded a 2‐mercaptopyrimido[5,4‐b]indole 18.
Arsenic containing heterocycles. II. Confirmation of the structure of benzo[a]‐9‐chlorophenarsazine 12‐chloride by 13C‐NMR spectroscopy and spin‐lattice relaxation time studies: Possible evidence for the contribution of an 75as‐13C mechanism to the relaxation of the arsenic bearing quarternary carbons in the phenarsazine ring system
Authors: Jay Michael , Martin Gary E. 
Published: March 2009

AbstractThe product of the reaction of (3‐chlorophenyl)‐2‐naphthylamine with arsenic trichloride has been confirmed to be benzo(a)‐9‐chlorophenarsazine 12‐chloride by 13C‐nmr spectroscopy and spin‐lattice (T1) relaxation time measurements. A considerable shortening of the spin‐lattice relaxation times of the arsenic bearing quaternary carbons, relative to the calculated relaxation times, was observed. This discrepancy has been interpreted in terms of an 75As‐13C dipolar contribution to quaternary carbon relaxation.
Synthesis and some reactions of hexahydro‐1,2,4‐triazine‐3,6‐dione
Authors: Schwan Thomas J. 
Published: March 2009

AbstractThe synthesis of hexahydro‐1,2,4‐triazine‐3,6‐dione by hydrogenolysis of 1,2‐dibenzylhexahydro‐1,2,4‐triazine‐3,6‐dione is reported. Ring contraction of the former dione to 3‐amino‐2,4‐imidazolidinedione is discussed. The preparation of the 1‐ and 2‐benzyl derivatives of hexahydro‐1,2,4‐triazine‐3,6‐dione and their conversion to the unsubstituted product are also described.
Novel rearrangements of N‐arylpyrrolyl sulphides
Authors: Cheeseman G. W. H. , Hawi A. A. 
Published: March 2009

AbstractBase treatment of the pyrrolylthioacetate 2 and the pyrrolylthioacetonitrile 4 unexpectedly yielded a pyrrolo[2,1‐b]thiazole 6 and 2‐(α‐cyano‐2‐nitrobenzyl)thiopyrrole (7), respectively.
A novel synthesis of 2‐aryl‐4‐piperidones by mannich cyclization of iminoketals
Authors: Bosch Joan , Rubiralta Mario , Moral Montserrat , Valls Maria 
Published: March 2009

Abstract2‐Aryl‐4‐piperidones have been synthesized by condensation between an aromatic aldehyde and a β‐aminoketone ethylene ketal, and further cyclization of the resulting iminoketal with dry hydrogen chloride or anhydrous p‐toluensulfonic acid. Alternatively, reaction of the above iminoketals with methyl fluorosulfonate followed by dry hydrogen chloride treatment and acid hydrolysis gives directly N‐methyl‐4‐piperidones. The application of these reactions to the synthesis of some 2‐aryl‐3‐acetylpyrrolidine systems is also described.
Anticonvulsant property of substituted 5‐aryltetrazol‐2‐ylacetylcarbamides
Authors: Jaiswal R. K. , Jaiswal Neelam , Parmar S. S. , James E. C. 
Published: March 2009

AbstractEight 1‐(5‐aryltetrazool‐2‐ylacetyl)3‐substituted carbamides were synthesized as possible anticonvulsants. The anticonvulsant activity possessed by these substituted tetrazolylacetylcarbamides was reflected by their ability to provide 10‐50% protection against pentylenetetrazol(1,5‐pentamethylenetetrazol)‐induced convulsions in mice. These substituted tetrazolylacetylcarbamides possessed low monoamine oxidase inhibitory activity, and the degree of enzyme inhibition ranged from 22‐47% at a final concentration of 1 mmole using kynuramine as the substrate.
Electrochemical synthesis of heterocyclic compounds. XII. Anodic oxidation of catechol in the presence of nucleophiles
Authors: Tabaković Ibro , Grujić Zdravko , Bejtović Zlatko 
Published: March 2009

AbstractThe electrochemical synthesis of coumestan derivatives and some related heterocyclic system (2a‐11a) by anodic oxidation of catechol (1) in the presence of various nucleophiles 2‐11 is described. Products were obtained in good yields and purity. The mechanism of oxidation was deduced from voltammetric data and by coulometry at controlled potential.
Activated nitriles in heterocyclic synthesis. A novel synthesis of pyrazolo[1,5‐a]pyrimidines and pyrano[2,3‐c]pyrazoles
Authors: Elfahham Hassan Attia , Abdel‐Galil Fathy Mohamed , Ibraheim Yusria Rizk , Elnagdi Mohamed Hilmy 
Published: March 2009

AbstractSeveral new pyrazolo[1,5‐a]pyrimidines and pyrano[2,3‐c]pyrazoles were synthesized viathe reaction of the cinnamonitrile derivatives 1a‐c with 5‐amino‐3‐phenylpyrazole (1), 3‐amino‐2‐pyrazolin‐5‐one (2) and 3‐amino‐1‐phenyl‐2‐pyrazolin‐5‐one (22).
The synthesis of pyridoquinolines with dialkylaminopropylamine side chains
Authors: Molock Frank F. , Boykin David W. 
Published: March 2009

AbstractSeveral new pyridoquinolines with dimethylaminopropyl side chain including 4,7‐bis(3′‐dimethylaminopropylamino)‐1,10‐phenanthroline (1), 4,10‐bis(3′‐dimethylaminopropylamino)‐1,7‐phenanthroline (2), 4,10‐bis(3′‐dimethylaminopropylamino)‐6‐methyl‐1,7‐phenanthroline (3), 4,6‐bis(3′‐dimethylaminopropylamino)‐10‐methylpyrido[3,2‐g]quinoline (4) and 4‐(3′‐dimethylaminopropyl)pyrrolo[lmn][4,7]phenanthroline (5) have been prepared. The compounds were prepared by a multi‐step synthesis which begins with Michael type addition of dimethyl acetylenedicarboxylate or diethyl ethoxymethylenemalonate to the appropriate phenylenediamine. The enamines obtained from the Michael addition were cyclized on heating at elevated temperatures to form the corresponding pyridoquinoline‐diester‐diones. The diester‐diones were saponified decarboxylated and converted into dichloropyridoquinolines which on reaction with dimethylaminopropylamine yielded the title compounds.
A one‐step conversion of N‐acylaminoketones into 5‐alkylidene‐3‐pyrrolin‐2‐ones
Authors: Anselmi Cecilia , Camparini Alfredo , Scotton Mirella 
Published: March 2009

AbstractA simple and efficient one‐pot synthesis of 5‐alkylidene‐3‐pyrrolin‐2‐ones 3a,e‐g from N‐acylaminoketones is described. A mechanism is proposed and it is substantiated by synthethising and converting the proposed intermediates into the pyrrolinones 3a,e‐g.
Reaction of 1,3‐diaryl‐2,3‐dibromo‐1‐propanones with urea in basic and acidic medium. Synthesis of pyrimidine, imidazoline and imidazolidine derivatives
Authors: Dora E. Khalli , Dash Bhabagrahi , Panda C. S. 
Published: March 2009

AbstractReaction of 1,3‐diaryl‐2,3‐dibromo‐1‐propanones 1 with urea in basic medium afforded 4,6‐diaryl‐5‐bromo‐5,6‐dihydropyrimidine‐2(1H)‐ones 4. Oxidation of these bromopyrimidines 4 in dimethylsulphoxide gave 4,6‐diaryl‐1,6‐dihydropyrimidine‐2,5‐diones 6, which were further converted to their thione analogues 7. Reaction of 1,3‐diaryl‐2,3‐dibromo‐1‐propanones 1 with urea, phenylurea and sym‐diphenylurea in glacial acetic acid medium gave in appreciable yields 4‐phenyl‐5‐α‐(bromoarylmethyl)imidazolin‐2‐one 8 and 1,3‐diphenyl‐4‐aroyl‐5‐arylimidazolidin‐2‐one 11 respectively.
Studies on the synthesis of heterocyclic compounds. XI. Cleavage of 1,3‐benzodioxoles by magnesium bromide‐acetic anhydride
Authors: Bonsignore Leonardo , Fadda Anna Maria , Loy Giuseppe , Maccioni Antonio , Podda Gianni 
Published: March 2009

AbstractThe cleavage reaction of some 1,3‐benzodioxole derivatives with magnesium bromide and acetic anhydride has been studied. The reactions have been carried out in acetonitrile solution at room temperature. In all of the 1,3‐benzodioxoles studied, the opening of the heterocyclic ring with formation of bromides, alkenes and their corresponding products of hydrolysis have been observed. The competitive electrophilic substitution on the benzene ring was very limited and was insignificant when a large excess of the cleavage reagent was used. The structures of newly prepared compounds have been determined by elemental analysis, spectroscopic data and comparison with authentic samples.
An ESR study of the cation radicals of azodibenzothiazolyls
Authors: Okada Keiichi , Yamauchi Jun , Deguchi Yasuo 
Published: March 2009

AbstractMethyl and ethyl derivatives of thiobenzothiazole and their quaternary salts were prepared by the sealed glass tube method. Azinodibenzothiazoles were oxidized by lead(IV) acetate, giving cation radical salts with the boron tetrafluoride anion moiety. The well‐resolved esr spectra observed were analyzed by comparing the data with those of a deuteriomethylated radical and with those from the MO calculations. Spin density distribution was consistently determined by computer simulation, including almost the same unpaired electron distribution on the four nitrogen atoms.
Aspects of the preparation of cyclohexenyl‐ and menthenylthioenynes via ring‐opening of thiophenes
Authors: Svensson Arne , Karlsson J. Olle , Hallberg Anders 
Published: March 2009

AbstractTreatment of 2,5‐dimethyl‐3‐(1‐menthenyl)4‐bromothiophene (IIIa) and 2,5‐dimethyl‐3‐(1‐cyclohexenyl)4‐bromothiophene (IIIb) with butyllithium gave the thiodienynes Va and Vb, respectively, via ring‐opening of the corresponding 3‐lithio derivatives. 2,5‐Dimethyl‐3‐(1‐menthenyl)‐4‐bromothiophene 1,1‐dioxide (IV) gave the sulfone VI under similar conditions. The uv spectra of IIIa‐b, IV, Va‐b and some related compounds have been recorded and compared. The rotational barrier of compound VI was determined.
Dialkyl bicyclic heterocycles with a bridgehead nitrogen as purine analogs possessing significant cardiac inotropic activity
Authors: Okabe Takayuki , Bhooshan Bharat , Novinson Thomas , Hillyard Ira W. , Garner Garland E. , Robins Roland K. 
Published: March 2009

AbstractA number of 5,7‐dialkyl‐s‐triazolo[1,5‐a]pyrimidines and 5,7‐dialkylpyrazolo[1,5‐a]pyrimidines and related heterocycles containing a bridgehead nitrogen have been prepared and studied as cardiovascular agents in the anesthetized dog. A number of these compounds have exhibited significant inotropic activity with little effect on heart rate. Especially active were 5,7‐dialkyl‐2‐amino or 2‐alkylthio‐s‐triazolo[1,5‐a]pyrimidines. In contrast, highly polar purine analogs in these ring systems compounds such as 5,7‐di‐n‐propyl‐2‐benzylthio‐1,3,4‐thiadiazolo[3,2‐a]pyrimidine bromide 45 containing a charge on the bridgehead nitrogen, were inactive. The detailed structure activity relationship of the dialkyl derivatives of related ring systems are discussed. The presence of certain ring nitrogen atoms are vital to potent in vivo activity, presumably due to specific enzyme binding at these sites. Several of the compounds studied, showed oral activity and are excellent can‐diates for further evaluation in man.
The chemistry of 5‐hydroxy‐6‐(hydroxyalkyl)uracils. Synthesis of spiro[pyrimidine‐4,2′‐pyrano[3,2‐d]pyrimidines]
Authors: Sasson Isaac M. , Gagnier R. Paul , Otter Brian A. 
Published: March 2009

AbstractBoth 5‐acetoxy‐6‐(acetoxymethyl)‐1‐methyluracil 1 and its parent diol 11 are converted into the spiro[pyrimidine‐4,2′‐pyrano[3,2‐d]pyrimidine] 6 when treated, respectively, with hot methanolic pyridine and with one equivalent of acetic anhydride. The formation of 6 can be explained in terms of the generation and dimerization of the reactive 5‐oxo‐6‐methylene pyrimidine 2. The structure of 6 was determined by 13C nmr spectroscopy and by chemical transformations that lead to the pyrimidinylethylhydantoin 9 and the 6,6′‐[1,2‐ethanediyl]bispyrimidine 10. The more complex 5‐hydroxy‐6‐(hydroxyalkyl)uracils represented by the 6,5′‐cyclourid‐ines 17 undergo an analogous dimerization when treated with acetic anhydride to give structures 22a and 22b. Dimer 22a was also prepared via the 5‐phosphate ester 18. The stereochemistry of dimers 22a and 22b, which is apparent from their 1H nmr spectra, indicates that two molecules of the enones 21a or 21b dimerize in a highly stereoselective manner.
Synthesis of some benzopyranocyclopentapyridine and pyranoacridine derivatives
Authors: Merchant J. R. , Martyres Gail , Koshti N. M. 
Published: March 2009

AbstractAminocoumarins react with ethyl cyclopentanone‐and ethyl cyclohexanone‐2‐carboxylates to afford intermediates which on thermal cyclisation yield the title compounds.
Some 4‐alkyl s‐triazolo[4,3‐a]quinoxalines
Authors: Campaigne E. , Mclaughlin A. R. 
Published: March 2009

AbstractA number of higher homologs of 4‐alkyl 2‐triazolo[4,3‐a]quinoxalines, some of which have a methyl or di‐chloromethyl group at position 1, have been prepared and characterized.
Quinazolines and 1,4‐benzodiazepines. XCIV. Pyrazino[1,2‐a][1,4]benzodiazepines
Authors: Walser A. , Flynn T. , Fryer R. I. 
Published: March 2009

AbstractA series of pyrazino[1,2‐a][1,4]benzodiazepines were prepared by acylating the primary amino group of an α‐amino‐1,4‐benzodiazepine‐2‐ylideneacetic acid ester (1) with α‐chloroacyl chlorides followed by cyclo‐dehydrohalogenation with triethylamine in dimethylformamide. Some pharmacological data for CNS‐activity are discussed.
A template effect in the synthesis of dibenzo‐14‐crown‐4 derivatives
Authors: Chen C. S. , Wang S. J. , Wu S. C. 
Published: March 2009

AbstractA new series of 4‐substituted derivatives of dibenzo‐14‐crown‐4 including 4‐nitro‐DB14‐crown‐4 (2a), 4‐bromo‐DB14‐crown‐4 (2b), 4‐chloro‐DB14‐crown‐4 (2c) and 4‐formyl‐DB14‐crown‐4 (2d) has been synthesized with and without a lithium cation template. No matter with or without the template, a satisfactory correlation between the nature of the substituent group on the benzene ring and the reaction yield is observed. The larger σ values for the substituent groups gave lower yields.
The sulfenylation of substituted imines
Authors: Seitz David E. , Needham Fang‐Ling 
Published: March 2009

AbstractConditions for mono‐ and bissulfenylation of N‐methyl‐3,3‐dimethylpyrrolidine‐2,5‐dione are described and compared to a closely related six‐membered imide, N‐methyl‐3‐ethyl‐3‐phenylpiperidine‐2,6‐dione. The influence of solvent, base and electrophile on product distribution is explored.
Synthesis of some new fluorophenothiazines
Authors: Tambi S. B. , Anand Madhu , Taneja Vineeta , Gupta C. L. , Mital R. L. 
Published: March 2009

AbstractThe synthesis of various 3‐substituted derivatives of 7‐fluorophenothiazin‐3‐ol and their 5‐oxides is described. The ir, uv and mass spectral data are also included.
Synthesis of isonipecotinoyl analogues of aminopterin and folic acid
Authors: Sekikawa Isao , Takahashi Yumiko 
Published: March 2009

AbstractThe preparation of isonipecotinoyl analogues of aminopterin and methotrexate is described. Condensation of diethyl N‐isonipecotinoyl‐L‐glutamate 4 with 2‐amino‐5‐bromomethyl‐3‐cyanopyrazine 5 afforded diethyl N‐(N‐[(2‐amino‐3‐cyanopyrazin‐5‐yl)methyl]isonipecotinoyl)‐L‐glutamate 6. Cyclisation of 6 with guanidine followed by blocking group hydrolysis afforded N‐([N‐(2,4‐diaminopteridin‐6‐yl)methyl]isonipecotinoyl)‐L‐glutamic acid 8. Coupling of N‐(2‐amino‐4(3H)ioxopteridin‐6‐yl]methyl)isonipecotinic acid 11 with diethyl L‐glutamate gave diethyl N‐[(N‐[2‐amino‐4(3H)‐oxopteridin‐6‐yl]methyl)isonipecotinoyl]‐L‐glutamate 12. Blocking group hydrolysis afforded N‐[(N‐[2‐amino‐4(3H)‐oxopteridin‐6‐yl]methyl)isonipecotinoyl]‐L‐glutamic acid 13.
Oxidation reactions of indapamide. A novel route to the indole derivative, N‐(3‐sulfamyl‐4‐chlorobenzamido)‐2‐methylindole
Authors: O'Hare M. J. , Tan E. , Rehm C. , Grebow P. , Loev B. , Neiss E. 
Published: March 2009

AbstractIndapamide (1) is readily oxidized with mild oxidizing agents to the indole derivative 2. Dehydrogenation of indapamide is a convenient one step synthesis of a complex indole compound.
4‐Alkyl(aryl)‐3‐amino‐1,2,5‐thiadiazole 1,1‐dioxides
Authors: Pietruszkiewicz Adolph M. , Baldwin John J. , Bolhofer William A. , Hoffman Jacob M. , Lumma William C. 
Published: March 2009

AbstractTwo methods have been developed for the synthesis of 3‐amino‐1,2,5‐thiadiazole 1,1‐dioxides; one leads to 4‐alkyl derivatives, the other to 4‐aryl analogs.
Diaminopyridazine aus diaminocyclopropenyliumsalzen und (diazomethyl)‐ verbindungen
Authors: Heydt Heinrich , Eisenbarth Philipp , Feith Karin , Regitz Manfred 
Published: March 2009

AbstractDiaminocyclopropenyliumsalze (14a,b) reagieren in Dichloromethan mit den phosphorylierten Diazomethanen 15a‐e in Gegenwart von Ethyl‐diisopropylamin bzw. 1,5‐Diazabicyclo[4.3.0]non‐5‐en spezifisch zu den 4,5‐Diaminopyridazinen 16a‐f. Aus dem Salz 14c und den Diazomethylverbindungen 15a,c,d sowie f‐k in Dichlormethan im Beisein der bicyclischen Base bilden sich dagegen die 3,4‐Diaminopyridazine 17a‐i. In mechanistischer Hinsicht ist die Bildung intermediär auftretender (Diazomethyl)cyclopropene (14a,b + 15 → 18) bzw. (14c + 15 → 19) im Sinne der elektrophilen Diazoalkansubstitution zu interpretieren; weder 18, noch 19 lassen sich isolieren, sondern gehen eine rasche [1,5]‐Cyclisierung zu den Betainen 20 bzw. 21 ein, die abschließend durch Öffnung der Brückenbindung zu den Pyridazinen 16 bzw. 17 isomerisieren.
4‐Hydroxy‐6‐methyl‐2‐pyrone (triacetic acid lactone) and its 3‐phenylthiomethyl derivative towards aldehydes in the presence of piperidine
Authors: Moreno‐Mañas M. , Papell E. , Ribas J. , Virgili A. , Pleixats R. 
Published: March 2009

AbstractAldehydes react with triacetic acid lactone, 1, in the presence of piperidine to afford the pyrones 3a‐d and 5. The intermediacy of quinone‐methides of type 2a‐e has been postulated, and experimental evidence for their existence has been achieved by generation by thiophenol elimination from 7 and subsequent trapping in Diels‐Alder reactions. Two examples are given in reactivity of 7 at the sluggish C‐5 position.
Synthesis of pyrido[2,3‐d]pyrimidin‐4‐one derivatives
Authors: Monge A. , Martinez‐Merino V. , Fernández‐Alvarez E. 
Published: March 2009

AbstractThis paper describes one‐pot synthesis of 5H‐[1,3]thiazolo[3,2‐a]pyrido[3,2‐e]pyrimidin‐5‐one 4, 5H‐dipyri‐do[1,2‐a:3′,2′‐e]pyrimidin‐5‐one 10 and 5H‐pyrido[3,2‐e]pyrimido[1,2‐a]pyrimidin‐5‐one 15 and some of their derivatives, starting with 2‐chloro‐3‐pyridine carboxilic acid 1. Compounds 4 and 10 reacted with phosphorus pentasulfide to give the respective 5‐thione analogues, 5 from 4 and 11 from 10.Boiling the 5‐thione derivatives with hydrazine hydrate, the respective 5‐hydrazono derivatives 6 from 5 and 12 from 11 were obtained. The 5‐acetyl hydrazono, 7, and the 5‐isopropylidenehydrazono, 8, derivatives were also prepared from 6, and the 5‐propionylhydrazono derivatives, 13, from 12.Compound 4 reacted with hydrazine to give an adduct with two molecules of hydrazine and the probable structure 16. Treating this adduct with acetone a monohydrazone 17 was obtained. Boiling a suspension of this adduct in DMF, it gave 6,10‐dihydro‐6H‐pyrido[3′,2′:5,6]pyrimido[2,1‐c][1,2,4]triazin‐5‐one 20.
Synthesis and antitumor evaluation of some 1,3‐disubstituted tetrahydropyrimido[4,5‐c]isoquinolines
Authors: Gangjee Aleem , Ohemeng Kwasi A. , Lin Fu‐Tyan , Katoh Arthur A. 
Published: March 2009

AbstractCyclocondensation of 6‐amino‐2,4‐dioxopyrimidine or 2,4,6‐triaminopyrimidine with 1‐cyclohexenecarbox‐aldehyde13afforded regiospecifically, tricyclic, angular 1,3‐disubstituted tetrahydropyrimido[4,5‐c]isoquin‐olines5and6respectively. In addition, 2,4,6‐triaminopyrimidine when condensed with 2‐chloro‐1‐cyclohex‐enecarboxaldehyde14, regiospecifically afforded the angular isomer6. However, the cyclocondensation of 2,6‐diamino‐4‐oxopyrimidine with13was regioselective and afforded a mixture of the linear and angular tetrahydropyrimidoisoquinolines2and4. The growth of leukemia L‐1210 cells in culture were inhibited 50% by6at 9 × 10−8M.Compounds4and5were not significantly active.
Two‐dimensional NMR studies of marine natural products. IV. Isolation of the cembranoid diterpene jeunicin from the mollusc planaxis sulcatus: Assignment of the proton and carbon NMR spectra by two‐dimensional techniques
Authors: Sanduja Radhika , Linz Gary S. , Alam Maktoob , Weinheimer Alfred J. , Martin Gary E. , Ezell Edward L. 
Published: March 2009

AbstractNumerous cembranoic diterpenes have been isolated from marine gorgonians and terrestrial plants. There have, however, been only a few reports of the isolation and identification of these interesting compounds from higher animal sources. The isolation of the oxo‐bridged cembranoid diterpene jeunicin from the mollusc Planaxis sulcatus is reported. A comparative discussion of the utility of COSY, homonuclear RELAY (relayed COSY) and proton double quantum coherence techniques is presented, the latter successfully establishing the identities of all of the proton resonances. Acquisition of a two‐dimensional proton‐carbon chemical shift correlation spectrum provided the means of unequivocally establishing 13C resonance assignments.
Synthesis of 1H‐imidazo[1,2‐a]imidazole
Authors: Compernolle Frans , Toppet Suzanne 
Published: March 2009

AbstractThe synthesis and structure analysis of the unknown 1H‐imidazo[1,2‐a]imidazole (1) is described. The preparation involves alkylation of 2‐aminoimidazole with bromoacetaldehyde diethyl acetal and subsequent hydrolysis and cyclization with hydrochloric acid. The structure was characterized by mass spectrometry and by 1H‐, 15N‐ and 13C‐nmr of 1 and by 1H‐nmr of its 1‐benzyl derivative 8. An independent synthesis of 8 was accomplished via cyclization of 2‐(N‐dichloroethyl‐N‐benzyl)aminoimidazole (11).