Synthesis of Novel Phosphorylated Guanidine Derivatives from Cyanamide and Their Anti-inflammatory Activity

Abstract

A series of novel guanidine derivatives were synthesized in three steps and their anti-inflammatory activities in vitro and in vivo evaluated. 2-Aminopyridin-3-ol (1) was reacted with thiophosphoryl chloride (2) to give a monochloride (3). It was further reacted with cyanamide to afford the corresponding cyanamine (4), which was subsequently reacted with different heterocyclic amines to form the title compounds (5a–l). The substituent in the guanidine function affected the potency of anti-inflammatory activity. The compounds having benzothiazole, fluorophenyl, and piperazinyl moieties enhanced the anti-inflammatory activity.