Highly Efficient Regioselective Synthesis of 2-Imino-4-oxothiazolidin-5-ylidene Acetates via a Substitution-Dependent Cyclization Sequence under Catalyst-Free Conditions at Ambient Temperature

详细信息    查看全文

• 作者：Yogesh B. Wagh ; Anil S. Kuwar ; Dipak R. Patil ; Yogesh A. Tayade ; Asha D. Jangale ; Santosh S. Terdale ; Darshak R. Trivedi ; Judith Gallucci ; Dipak S. Dalal
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2015
• 出版时间：October 14, 2015
• 年：2015
• 卷：54
• 期：40
• 页码：9675-9682
• 全文大小：415K
• ISSN：1520-5045

文摘

A green and efficient method for the synthesis of newer 2-imino-4-oxothiazolidin-5-ylidene acetate derivatives under catalyst-free conditions by simply stirring symmetrical and unsymmetrical 1,3-diarylthioureas with dialkyl acetylenedicarboxylates in ethanol at room temperature has been developed. Interestingly, the regioselective synthesis affords the 2-imino-4-oxothiazolidin-5-ylidene acetate derivatives: the amine nitrogen bonded to an electron-withdrawing substituent becomes part of the imino component, and the amine nitrogen bonded to an electron-donating substituent becomes the heterocyclic nitrogen. This is the first report wherein the impact of substituents in directing the regiocyclization has been explained and the structure conflict resolved by single-crystal X-ray analysis.