Synthesis, Reactions and Antimicrobial Activities of 8-Ethoxycoumarin Derivatives

Abstract

Condensation of 3-acetyl-8-ethoxycoumarin (3) with thiosemicarbazide gave ethylidenehydrazinecarbothioamide 5, which was transformed into the thiazolidin-4-one derivatives 6,7. Interaction of 3 with DMF/POCl3 gave β-chloroacroline derivative 8. Treatment of 3 with malononitrile gave benzo[c]chromone and 2-aminobenzonitrile derivatives 9 and 10, respectively with respect to the reaction conditions. Condensation of 3-(2-bromoacetyl)-8-ethoxycoumarin (4) with o-phenylenediamine gave 3-(quioxaline-2-yl)-8-ethoxycoumarin hydrobromide (11), while 4 reacted with 2-aminopyridine to give chromenopyridopyrimidine derivative 12. Condensation of 4 with potassium thio-cyanate/methanol gave an unexpected derivative, 2H-chromeno-3-carboxy(methyl-carbonimidic)thioanhydride 16, which upon treatment with (NH2)2·H2O gave 3-ethoxy-2-hydroxybenzaldehyde azine 19. Interaction of 4 with thiourea derivatives gave thiazole derivatives 20a–c. The structures of the newly synthesized compounds were confirmed by their spectra data. The newly synthesized compounds were also screened for their antimicrobial activity.

A Facile Synthesis of Oxoindenothiazine and Dioxospiro(indene‐2,4′‐thiazine) Derivatives from (Substituted ethylidene)hydrazinecarbothioamides

“…2-(1-Phenylethylidene)hydrazinecar bothioamide 5a, 2-[1-(furan-2-yl)ethylidene]hydrazinecarbo thioamide 5b, 2-[1-(pyridin-3-yl)ethylidene]hydrazinecar bothioamide 5c, N-phenyl-2-(1-phenylethylidene)hydrazine carbothioamide 5d, N-benzyl-2-(1-phenylethylidene)hydra zinecarbothioamide 5e, and N-allyl-2-(1-phenylethylidene) hydrazinecarbothioamide 5f were prepared by the reaction of thiosemicarbazides (or 4-substituted thiosemicarbazides) with the proper ketone according to the published procedures [29,30]. (1,3-Dioxo-2,3-dihydro-1H-inden-2-ylidene)propanedinitrile (CNIND, 1) was prepared and purified according to the published procedures [31].…”

Novel Synthesis of 1,3‐Thiazine and Pyrimidinethione Derivatives from (1‐Aryl ethylidene)hydrazinecarbothioamides and Tetracyanoethylene

“…2‐(1‐Phenylethylidene)hydrazinecarbothio‐amide 6a , 2‐[1‐(furan‐2‐yl)ethylidene]hydrazinecarbothio‐amide 6b , 2‐[1‐(pyridine‐3‐yl)ethylidene]hydrazinecarbothioamide 6c were prepared by the reaction of thiosemicarbazide with the proper ketones according to the published procedures. Ethenetetracarbonitrile (TCNE, 2 , Merck) was purified by crystallization from chlorobenzene and sublimed.…”

Synthesis and Biological activity of 1,3-Thiazolylidenehydrazinylidene ethylpyridiniumbromide monohydrate, 1,3-Thiazolylidenehydraziniumbromide and 1,3-Thiazolylidenehydrazine derivatives

“…2-(1-Substituted ethylidene)hydrazinecarbothioamides 1a-h were prepared by condensation 4-phenylthiosemicarbazide with the appropriate ketones according to the published procedures [41,42]. 1 -Aryl-2-bromoethanones (2a,b) were prepared according to Nobuta and Salama [43,44].…”