摘要
A convenient one-step synthesis of five-membered or six-membered imino-protected cyclic guanidine via an intramolecular ring-closure reaction of alkyl diamine（2a-2g） with 1,3-diamino-protected methylisothiourea（1a and 1b） was established and investigated.Amino guanidine such as 3-（2-aminoethyl）-1,2-dibenzyloxycarbonylguanidine（4a） has been proved to be the intermediate of the reaction via utilizing mono-protected diamine as starting material.The intramolecular ring closure of 4a results in 2-benzyloxycarbonyliminoimidazolidine（3a）.This new one-step synthesis has advantages of simple condition,easy workup procedure and reasonable yield.
A convenient one-step synthesis of five-membered or six-membered imino-protected cyclic guanidine via an intramolecular ring-closure reaction of alkyl diamine（2a-2g） with 1,3-diamino-protected methylisothiourea（1a and 1b） was established and investigated.Amino guanidine such as 3-（2-aminoethyl）-1,2-dibenzyloxycarbonylguanidine（4a） has been proved to be the intermediate of the reaction via utilizing mono-protected diamine as starting material.The intramolecular ring closure of 4a results in 2-benzyloxycarbonyliminoimidazolidine（3a）.This new one-step synthesis has advantages of simple condition,easy workup procedure and reasonable yield.
基金
Project 81001366 supported by NSFC and basic scientific research foundation of Institute of Materia Medica(No.2009CHX07) for financial support.
