5‐Amino‐3‐phenylpyrazole (I) and 5‐amino‐4‐bromo‐3‐phenylpyrazole (II) reacted with ethyl acetoacetate and acetylacetone to give various pyrazolo[1,5‐a]pyrimidines IV‐VI and with benzoins to give different fused pyrazoles, namely, imidazo[1,2‐b]pyrazoles IX, pyrrolo[2,3‐c]pyrazoles X and pyrazolo[4,3‐b][1,4]oxazines XII. Diazotized II was coupled with active methylene‐containing nitriles to afford pyrazolo[5,1‐c]‐as‐triazines XIV.
The reactivity of heterocyclic α,β-unsaturated ketones towards the title compounds has been studied. A pyrimidine, pyrazoline, isoxazoline and a fused pyrrolidine rings have been built up. Mannich reaction was tried with the pyrazoline derivative (4 d). Bromination of the 2-cinnamoyl compounds (1 a-c), and cyclization of the products were also undertaken.
Whereas acetoacetanilide (II) reacted with α‐cyano‐ and α‐benzoylcinnamonitrile derivatives Ia‐e to give hexa‐substituted pyridines III and V, it reacted with α‐carboxamido‐ and α‐thiocarboxamidocinnammonitrile derivatives If‐h to afford penta‐substituted pyridines VI. One mole of acetonedicarboxylic acid dianilide (VII) reacted with two moles of each of α‐cyano‐ and α‐thiocarboxamidocinnamonitriles Ia,b,f,g to yield the dipyridyl ketones VIII and IX, respectively. On the other hand, α‐benzoyl‐ and α‐ethoxycarbonylcinnamonitriles Ic,d,i,j reacted with VII in equimolecular ratio to give the pyran derivaties X and XI, respectively. Several schemes were proposed to illustrate reactions steps. The structures of the synthesized compounds were proved by chemical and spectral methods.
5‐Salicylidenethiazolidine‐2,4‐dithione (1) reacts with acrylonitrile, N‐phenylmaleimide and dimethyl acet‐ylenedicarboxylate to afford the fused thiopyrano[2,3‐d]thiazolidinethione derivatives 2, 4 and 6, respectively. The salicylidene derivative 1 reacts with ethyl acrylate and malononitrile to afford the fused [1]benzopyrano[3′,4′:4,5]thiopyrano[2,3‐d]thiazoles 3 and 9, respectively. 4‐Phenylhydrazono‐2‐thiazolidinethione (11) reacts with ethyl bromoacetate and/or phenacyl bromide to yield the fused thiazolo[3,4‐c]triazines 13 and 14.
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EgyptSome 2-aryl-1,3,4-thiadiazoline-5-thiones 1 react with formaldehyde to give the compounds 2, which react with thionyl chloride to afford the compounds 3. The latter react with phenols, thiophenol and related compounds giving 4. With amines, 3 yield the 2-aryl-4-alkyl(aryl)aminomethyl-l,3,4-thiadiazoline-5-thiones 7. Some of the compounds described were screened bacteriologically.
Einige Reaktionen von 2-Aryl-4-chlormethyl-1,3,4-thiadiazolin-5-thionenEinige 2-Aryl-l,3,4-thiadiazolin-5-thione 1 reagieren mit Formaldehyd zu 2, dieses reagiert mit Thionylchlorid zu 3. Verbindung 3 reagiert mit Phenolen, Thiophenol und venvandten Verbindungen zu 4. Mit Aminen gibt 3 2-Aryl-4-alkyl(oder aryl)aminomethyl-l,3,4-thiadiazolin-5-thione 7. Einige ausgewahlte Verbindungen wurden auf ihre Aktivitat gegen Bakterien untersucht.Some 5-mercapto-1,3,4-thiadiazoles are valuable pharmaceutical intermediates. They have a depressant effect on the central nervous system') and show antituberculous a~tivity"~'. This induced the authors to prepare some of their derivatives and to test their biological activity.2-Phenyl-l,3,4-thiadiazoline-5-thione (la) was reportedF7) to react with formaldehyde to give the 4-hydroxymethyl derivative 2a which reacts with thionyl chloride to afford the 4-chloromethyl derivative 3a. In the present investigation, the substituted phenyl derivatives 3b, c were similarly prepared from lb, c and some reactions of 3a-c were tried.
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