Синтез та циклофункціоналізація (1,3-тіазолідин-2-іліден)кетонів

• Date: 2018
• Main Authors: Litvinchuk, M. B., Bentya, A. V., Slyvka, N. Yu., Vovk, M. V.
• Format: Article
• Language: Ukrainian
• Published: National University of Pharmacy 2018
• Subjects: N-алілтіоаміди; електрофільна циклізація; (1; 3-тіазолідин-2-іліден)кетони; таутомерія; піроло[2; 1-b][1; 3]тіазоли; [1; 3]тіазоло[3; 2-a]піридини; УДК; 547.491.4 547.324 547.83 547.789
• Online Access: https://ophcj.nuph.edu.ua/article/view/ophcj.18.951
• Journal Title: Journal of Organic and Pharmaceutical Chemistry

Aim. To develop a new approach to the design of (1,3-thiazolidin-2-ylidene)ketones and expansion of their synthetic potential as convenient building blocks in the reactions of [3+2]- and [3+3]-cyclization.Results and discussion. Еlectrophilic intramolecular cyclization (EIC) of N-allythioamides of β-ketoacids using phosphoric acid or iodine is a convenient synthetic method to obtain new (5-methyl- and 5-iodomethyl-1,3-thiazolidine-2-ylidene)ketones. Cyclization of ketones with maleic anhydride leads to derivatives of 2,3-dihydropyrrolo[2,1-b][1,3]thiazole. [3+3]-Cyclocondensation with methyl propiolate and dimethyl acetylenedicarboxylate results in formation of the functionalized [1,3]thiazolo[3,2-a]pyridine derivatives.Experimental part. (5-Methyl- and 5-iodomethyl-1,3-thiazolidin-2-ylidene)ketones were synthesized from N-allylthioamides using phosphoric acid or iodine in chloroform. (1,3-Thiazolidin-2-ylidene)ketones react with maleic anhydride, methyl acetylenecarboxylate or dimethyl acetylenedicarboxylate resulting in a 2,3-dihydropyrrolo[2,1-b][1,3]thiazole-5(6H)-one and 2,3-dihydro-5H-[1,3]thiazolo[3,2-a]pyridine derivatives.Conclusions. A convenient method of [5-methyl- and 5-iodomethyl-1,3-thiazolidin-2-ylidene]ketones preparation based on the EIC of N-allylthioamides of β-ketoacids has been developed using phosphoric acid and iodine. The (1,3-thiazolidin-2-ylidene)ketones synthesized can be useful in cyclization reactions leading to functional pyrrolo[2,1-b][1,3]thiazole and [1,3]thiazolo[3,2-a]pyridine derivatives.