Showing papers in "Journal of Heterocyclic Chemistry in 1989"

TL;DR: In this paper, various reactions of 2-oxo(or thioxo)-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid derivatives (Biginelli-compounds) were investigated.

TL;DR: In this paper, the reactions of substituted benzyl azides with ethyl propiolate were found to be completely regiospecific, and they were used in a 1,3-dipolar cycloaddition with dimethyl acetylenedicarboxylate, phenylacetylene, and ethylpropiolate.

TL;DR: In this paper, the base-catalyzed cyclization of some N-propargylamides to oxazoles has been studied in the presence of sodium hydride and potassium carbonate.

TL;DR: In this paper, a short-time reaction of an amidoxime, RC(NH2)NOH, with an acyl chloride, R'COCl, in pyridine solution is described.

TL;DR: In this article, a series of 1-(1-carbonylmethyl-1H-benzotriazole) thiosemicarbazides 3a-e was synthesized and then cyclized with sodium hydroxide to afford 1-(4-substituted-4H-1,2,4-triazole-3-thion-5-yl)methyl-

TL;DR: In this article, the pyrrole, indole, and carbazole adducts undergo smooth lithiation at the inter-ring methylene group and subsequent reaction there with electrophiles.

TL;DR: In this article, a nucleophilic substitution-rearrangement was performed upon treatment with various primary amines at elevated temperatures to yield N-1-substituted 4-amino-1H-pyrrolo[3,2-c]pyridines (5-azaindoles).

TL;DR: In this article, 1-Phenyl-3,4-dichloromaleimide, 1-npropyl 3,3-brommaleimides, and 2-3-Dichloro-1, 4-naphthoquinone have been condensed with various mono-and bis-nucleophiles to yield a range of novel dyes and pigments.

TL;DR: In this paper, two isomeric 3-methyl-4-furoxancarbaldehydes (2a and 3b) and two 4-methyl isomerics (2b and 3c) have been prepared.

TL;DR: In this paper, a review described developments in the synthesis of heterocyclic compounds using carbon disulfide and their products and discussed the main challenges involved in the process of synthesizing these compounds.

TL;DR: In this paper, the three isomeric pivaloylaminopyridines were lithiated in more than 80% yields, using 2.5-3 equivalents of the complex BuLi-TMEDA at −10° in diethyl ether.

TL;DR: Improved procedures for the regioselective preparation of ethyl 1,5-diarylpyrazole-3-carboxylates are described in this paper, where the new procedures utilize readily prepared lithium aroylpyruvate intermediates which, when combined with arylphenylhydrazine hydrochlorides, form 1.5-Diaryl pyrazole 3-carboardylates with good yield.

TL;DR: The palladium-catalyzed cross-coupling reaction of 2-bromonitrobenzenes or 2bromoacetanilides with ethylene has been used to produce a variety of substituted indoles as mentioned in this paper.

TL;DR: In this article, all three isomeric hitherto unknown thieno[c]isoquinolines have been synthesized in high yields by the Pd(0)-catalyzed coupling of 2-formylbenzeneboronic acid with t-butyl-N-(ortho-halothienyl)carbaniates.

TL;DR: In this paper, a simple and convenient method to prepare polyaza-crowns and cyclams containing one or two unsubstituted macroring nitrogen atoms or a hydroxy group is described.

TL;DR: In this article, the synthesis of acyclic nucleoside analogs, 2-(2′,3′-dihydroxypropyl)-5-amino-2H-1,2,4-thiadiazol-3-one (1) and 3-( 2′, 3′-dimethyl-dyno-propyl)5amino,3H,1,3,4,thiadiadiadiamide-2-one(2), is reported.

TL;DR: Synthese des heterocycles du titre a partir de seleno ou thioamides et de chloro-3 acetylacetone as mentioned in this paper.

TL;DR: Methoxy, hydroxy and fluoro derivatives of 2′-carba-ganciclovir were prepared to examine the effect of re-introducing a binding site close to that in the original oxa side chain.

TL;DR: The reversible isomerization of 5-hydrazino-1,2,3-thiadiazoles and 1-amino-5-mercapto-1 2, 3-triazoles has been established for an ester function at the 4 position (4a ⇌ 5a) as mentioned in this paper.

TL;DR: In this paper, a new synthesis of substituted pyridine was reported, where the base catalyzed reaction of substituted chalcones with malononitrile using sodium ethoxide in ethanol at room temperature afforded 2,4-diaryl-5-cyano-6-ethoxypyridine.

TL;DR: In this paper, a strong ir band due to the C = N stretching mode of the macrocyclic moiety was observed at 1610 cm−1 and shifted slightly toward higher energy upon benzoylation.

TL;DR: In this article, the reaction of 1-ethoxycarbonylmethylpyridinium bromides 5a-k with nitro ketene dithioacetal, 1,1-bis-(methylthio)-2-nitroethylene (2), in the presence of triethylamine in ethanol gave the desired ethyl 2-methyl-thioindolizine-3-carboxylates 3a-K in good yields.

TL;DR: In this article, the structure of (2R,5S)-2-trichloromethyl-1-aza-3-oxabiciclo-[3.3.0]octan-4-one has been confirmed by X-ray diffraction analysis.

TL;DR: In this article, the reaction of 3,5-bis(trifluoromethyl)-1,3,4-oxadiazole (1a) with primary amines under a variety of conditions conveniently produced 4-substituted 4H-1.2.4-triazoles 4a in 26-85% yield.

TL;DR: In this article, the mechanisms involved in various stages of the Kindler Reaction are discussed, with particular attention especially to its most unusual feature: the movement of a carbonyl group from methylene carbon to methylene carb in an unbranched alkyl chain, or around a cycloalkyl ring.

TL;DR: In this article, a general synthesis of 3-amino-3-alkylpropenenitriles is described, which can be further transformed to 5-AMINO-3 -alkylisothiazoles.

TL;DR: Aryl aldehydes I reacted with 1-benzosuberone to yield the corresponding 2-arylidene-1-benzo-uberone II as discussed by the authors.

TL;DR: A modification of a previously reported synthesis of 1-methyluracil which simplifies the isolation of the compound is reported together with a refined X-ray analysis of the title compound as mentioned in this paper.

TL;DR: In this article, a method for the preparation of condensed pyranones is presented. But the method is not suitable for the extraction of condensed Pyranone derivatives, such as barbituric acid derivatives, pyrazolones and resorcinol.

TL;DR: In this paper, a novel synthesis of 3-amino-1,2-benzisoxazole (3) from 2-[(isopropylideneamino)oxy]benzonitrile (2) is described.