Simple approach towards phosphorus-substituted spiro 1,3,4-thiadiazolines

This study reports the first general, practical, and facile synthesis of phosphorus-substituted 1,3,4-thiadiazolines starting from phosphorylthioformic acid hydrazides and ketones. Various cyclic ketones were efficiently incorporated into spiro 1,3,4-thiadiazoline derivatives by a two-step sequence involving the heterocyclization with phosphorylthioformic acid hydrazides followed by the nitrogen acylation with acyl chlorides. The protocol is characterized by operational simplicity, readily available reagents, and functional group tolerance.

Automated summary

This study presents a novel and practical synthesis method for phosphorus-substituted 1,3,4-thiadiazolines using phosphorylthioformic acid hydrazides and ketones. The protocol demonstrates operational simplicity, availability of reagents, and tolerance towards different functional groups.