Analgesic activity of novel spiro heterocycles. 2-Amino-7-oxa-3-thia-1-azaspiro[5.5]undec-1-enes and related compounds

Publisher Website
Google Scholar
Abstract
(.+-.)-2-Amino-7-oxa-3-thia-1-azaspiro[5.5]undec-1-ene (1a) and many of its derivative exhibit significant activity in the phenylquinone writhing and yeast inflamed foot assays in mice. In order to develop structure-activity relationships, the related spiroheterocycles, (.+-.)-2-amino-7-oxa-3-thia-1-azaspiro[5.4]dec-1-ene (2), (.+-.)-2-amino-3-thia-1-azaspiro[5.5]undec-1-ene (3) and (.+-.)-2-amino-7-oxa-1-azaspiro[5.5]undec-1-ene (4), were examined. Of these, only 4 failed to show activity indicating that the analgesic properties displayed by compounds 1-3 are associated with the 2-amino-1,3-thiazine ring system. In the 2-acylimino series, a contribution to the observed activity on the part of the spiroannulated ether ring is suggested. Both 1a and its p-fluorobenzoyl derivative exhibit analgesic activity in the rat tail-flick assay.