Showing papers in "Journal of Heterocyclic Chemistry in 2002"

TL;DR: In this paper, a relationship between the pKa value and the number of carbon atoms in the hydrocarbon group for (CH 2 n ≤ 13) was derived for HL+ acids.

TL;DR: In this paper, the synthesis of 1-methyl-2,4,5-trinitroimidazole (MTNI) was investigated, and the physical properties of 1 were further characterized by X-ray diffraction.

TL;DR: The 1H-pyrazole-3-carboxylic acid was converted via reactions of its acid chloride with various alcohols or N-nucleo-philes into the corresponding ester or amide derivatives.

TL;DR: NBS was found to be an efficient catalyst for condensations of indoles with aldehydes or ketones in the absence of solvent this article, and was used for the first time in this article.

TL;DR: In this paper, a new efficient synthesis of 2-styryl-6,7-dichlorothiazolo[4,5-b] based fluorescent dyes was achieved by the condensation of 2methyl-6-7-DICD with selected 4-N,N-dialkylamino-linearaldehydes and hetero-dehydes in the presence of piperidine.

TL;DR: In this paper, 1-substituted-3-dimethylaminopropenones 1a-d reacted with acetylacetone and with ethyl acetoacetate to yield regioselectively 2,3,6-trisubstitized pyridines.

TL;DR: In this paper, 2-Aryl-2,3-dihydro-4(lH)-quinazolines have been prepared in a one-pot synthesis by samarium idoide (SmI2) promoted reaction of o-nitrobenzamide and aldehydes.

TL;DR: In this paper, the isolation and identification of degradants of a sample of the complex indoloquinoline alkaloid, cryptospirolepine, was undertaken after prolonged storage in DMSO solution using a combination of cryogenic NMR probe technology and CASE (Computer-Assisted Structure Elucidation) programs.

TL;DR: A series of m- and p-substituted anilides of benzoic acid, 2-thienoic acid and 2-furoic acid were prepared and their 1H and 13C nmr spectroscopic characteristics were examined as mentioned in this paper.

TL;DR: In this article, the structures of the newly synthesized compounds have been established on the basis of their analytical and spectral data, based on their spectral properties and properties of the new compounds.

TL;DR: In this paper, the reaction of 3-formylchromone (1) with 5-amino-1H-pyrazoles (2) in ethanol, afforded 6-(2-hydroxy-benzoyl)pyrazolo[1,5-a]pyrimidines (3a-g) in good yields.

TL;DR: In this article, 2H-1-benzopyran hemiacetal was synthesized by photocyclization reaction of traanso-aminocinnamoyl derivatives trans-1 and trans-o-hydroxycinnamoys derivatives trans4.

TL;DR: In this article, a new and efficient methodology was proposed to synthesize N-amino pyrazolo[4,3c]pyridin-4-ones 4 and N-AMINO pyrazolino[3,4-c]-pyridine[3.4]-polymorphic acid from vic-acetylenyl/hydrazido pyrazoles, which involves the intermediate synthesis of methyl esters of the carboxylic acid.

TL;DR: In this paper, reaction of pyrone or tetronic acid with o-phenylenediamine derivatives gave enaminone compounds, which allowed versatile access to different heterocyclic structures: when DMA derivatives or triphosgene was used, cyclization occurred through nitrogen.

TL;DR: In this article, the reaction of (E)-2-aroylmethyl-3-(2-furyl)-N'-(tosylaminocarbonyl) acrylohydrazides 3a-d followed by acid catalyzed cyclization to afford N-{6-aryl-4-[(E)- 2-furlmethylene]-1,2,3,4-tetrahydro-3-oxopyridazin-1 -ylcarbonyl}-p-toluene-

TL;DR: Various 5H-thiazolo[2,3-b]quinazoline-3,5[2H]-diones have been synthesized via simple and efficient methods as mentioned in this paper.

TL;DR: In this paper, a sequence of simple and effective reactions starting from phloroglucinol was used to synthesize substituted chalcones and flavones, and the initial hydroxyl groups were protected by methylation and in the final flavones the 5-OH group was selectively demethylated by means of AlBr3.

TL;DR: In this article, a novel potassium carbonate mediated synthesis of 2-amino-1,3-thia/oxa zoles, 2amino 1,3, 4-thiadiazines and 2-hydrazino- 1, 3, 4, 4thiadiadiazine has been described.

TL;DR: Azolylacetophenones 1 and 2 react with dimethylformamide dimethylacetal to yield enaminones 7,8 that were converted into azolylazoles via reaction with hydrazine and with hydroxylamine as discussed by the authors.

TL;DR: In this paper, 3-aryl-5-styryl-2-pyrazolines have been synthesized by the reaction of (E,E)-cinnamylideneace-tophenones with hydrazines.

TL;DR: Substituted S-(1-phenylpyrrolidin-2-on-3-yl)isothiuronium salts in weakly basic media undergo intramolecular recyclisation reaction in which the γ-lactam cycle is split and a thiazolidine cycle is formed as discussed by the authors.

TL;DR: These nakeunudes reacted with various nucleophilic reagents such as election-rich aromatic and heteroaromatic compounds like dialkylanilines, aminophenols, indoles, indolizines, and cyalazines to give the corresponding 3-methylthio-2,5-dioxo-1H-pyrroles.

TL;DR: A zincic phthalocyanine (Pc) derivative functionalized with four peripheral substituted tetrathiafulvalene (TTF) units has been synthesized.

TL;DR: In this article, the reaction of homophthalic anhydride and N-(1-methyl-1H-pyrrol-2-yl-methylidene)-benzylamine in boiling benzene afforded as a main product the expected substituted trans-1,2,3,4-tetrahydroisoquinoline-4-carboxylic acid 5.

TL;DR: In this paper, 2-Aminophenols react with an array of carboxylic acids in dioxane at 180° in the presence of tin(II) chloride to afford the corresponding 2-substituted benzoxazoles in good yields.