Showing papers in "Journal of Heterocyclic Chemistry in 2001"

TL;DR: In this article, the preparation of 1-alkyl(aralkyl)-3-methyl(ethyl)imidazolium bromides and chlorides is described.

TL;DR: A series of novel 3-(coumarin-4-yl)tetrahydroisoxazoles were synthesized from coumarin 4 carboxaldehyde 1 via the intermediate N-methyl nitrone 3 and N-phenyl or n-methyl hydrazones 11a,b.

TL;DR: In this article, a novel synthesis of the title compound was achieved by direct animation using Vicarious Nucleophilic Substitution (VNS) methodology, using 1,1,1-trimethylhydrazinium iodide with 3,5-dinitropyrazole in DMSO.

TL;DR: In this paper, a number of symmetrically 2,5disubstituted 1,3,4-oxadiazoles are quickly prepared by the reaction of aromatic acids with hydrazine dihydrochloride in a mixture of orthophosphoric acid and phosphorus pentoxide under microwave irradiation.

TL;DR: In this article, 3-aryl-5-cyanopyrazolo[3,4-b]pyridines were easily prepared from 3-amino5-arylpyrazoles and α-cyclanochalcones.

TL;DR: In this article, an efficient one pot access to variously substituted thieno[2,3-b]thiophene is described, and the title compounds were obtained from 1,3dicarbonyl or equivalent compounds, carbon disulfide and halomethyl derivatives in good to high yields and fully characterized.

TL;DR: In this article, 3-Acetylcoumarine was condensed with dimethylformamide dimethylacetal (DMFDMA) to yield the enaminone, which reacts readily with hydroxylamine and with hydrazines to yield coumarin-3-ylisoxazoles and coumarins- 3-ylpyrazoles respectively.

TL;DR: A series of substituted 3,4-dihydro-2-pyrimidones (DHPMs) was reacted with nitric acid under different reaction conditions.

TL;DR: In this paper, the preparation of pyrazolo[1,5-a]-, 1,2,4-triazolo[ 1,5a]- and imidazo[1.2]-pyrimidines substituted on the pyrimidine moiety by a 4-[(N-acetyl-N-ethyl)amino]phenyl group was described.

TL;DR: In this article, several aromatic and α,β-conjugated aromatic aldehydes were condensed with barbituric acid in methanol solution in the absence of acid or base as a catalyst.

TL;DR: In this article, a four-step synthesis of the PARP inhibitor 2-(4-trifluoromethylphenyl)benzimidazole-4-carboxamide (1, NU1077) is presented.

TL;DR: The title aldehyde 1 in the presence of ammonia gives the pyridine derivatives 9-11 respectively with acetylacetone, diethyl malonate and ethyl cyanoacetate, and the coumarinopyridines 25 and 26, respectively as discussed by the authors.

TL;DR: Synthesis of novel pyrazolopyrrolopyrazines is described with the aim to reach new specific PDE-5 inhibitors of potential clinical interest in male erectile dysfunction.

TL;DR: The Biginelli condensation method was used in this paper for the preparation of dihydropyrimidines using NaH and various electrophiles (ClCO2Et, TsCl, Ac2O, AcCl and PhCOCl) and the structure of all the new compounds was confirmed using FT-ir, 1H nmr, 13C nmr spectral and elemental analyses methods.

TL;DR: Triazapentadienium iodides as discussed by the authors are efficient intermediates in heterocyclic synthesis and react with ketenes, sulfenes, phenyl isocyanate or isothiocyanates and dimethyl acetylenedicarboxylate affording the corresponding dihydropyrimidinones.

TL;DR: The synthesis of new methylated thieno[2,3-a] and [3,2-b] carbazoles was achieved by a palladium-catalyzed cross-coupling, intramolecular reductive cyclization sequence of reactions as mentioned in this paper.

TL;DR: In this paper, a mixture of 7,8-diaminotheophylline with lead tetraacetate in refluxing toluene gave a mixture 3-amino-5,7-dimethylpyrimido[4,5-e][1,2,4]triazine-6, 8-dione (2) and 6-cyanoimino-1,3-dioxopyrimidin-6-yl)cyanamides (9a-c).

TL;DR: In this paper, the trifluoroacetaldehyde ethyl hemiacetal (TFAE) was used to synthesize α-trifluoromethyl hydroxy-pyridinemethanols.

TL;DR: In this article, 1,1,1-trifluoro-2,3-alkanediones were obtained from various aldehyde dialkylhydrazones and reacted with several diamines to afford trifluoromethylquinoxalines 3 and triffluoromethemylpyrazines 4 in good yields.

TL;DR: In this paper, a number of 4-arylpyridines, many methoxy substituted, were prepared by an efficient two-step method involving aryl Grignard addition to 1-methyl-4-piperidone and direct aromatization of the resulting 4-aryl-4 piperidinols.

TL;DR: Several enaminodienones prepared from substituted acetone and dimethylformamide dimethylacetal were used as precursors for synthesis of pyridines, pyranones and benzofurans.

TL;DR: The reaction of 1-(2-aminophenyl)pyrrole with aromatic or heteroaromatic aldehydes in ethanol and catalytic amounts of acetic acid leads to 4,5-dihydropyrrolo[1,2-a]quinoxalines in high yields as discussed by the authors.

TL;DR: In this paper, the precursors of carbazole derivatives such as 2-acetoxy-carbazole (2-4), 3-bromocarbazole and 3-nitro carbazoles (4) were described and the corresponding iododerivatives, 2a, 2b, 2c, 3a, 3b, 4a and 4b, were described.

TL;DR: In this paper, the base catalyzed cyclisation of N-[(Z)-2-amino-1,2-dicycanovinyl carbamoyl]-p-toluenesulfonamide 2 was shown to give 7,8-dihy-dro-2-(4-nitrophenyl)-8-oxo-9-tosylpurine-6-carboxamide 8.

TL;DR: In this article, the absolute stereochemistry of hyperolactones was unambiguously established by a synthesis of spirolactone skeleton by one-pot reaction as a key step.

TL;DR: In this paper, the reactions of 2-benzamido-4,5-dihydro-3-thiophene(and -3-furan)carbonitriles (1a-c and 4a-C) with ethyl acetoacetate in the presence of tin(IV) chloride and triethylamine provided the corresponding ethyl 2-(5,6dihdro-2-phenylthieno(and furo)[2,3-d]pyrimidin-4-yl)propan

TL;DR: In this paper, 1-Benzoyl-2-phenyl-4-(4′-methoxyphenyl)-[1,4]-benzodiazepine (IIa) was formed through benzoylation of starting material 2phenyl with the inversion of seven-member ring boat conformation.

TL;DR: In this paper, a four-step synthesis of aminobicyclopyrazolone hydrochloride 1·HC1 was achieved starting from di-tert-butyl hydrazodiformate (8).