SYNTHESIS OF SYDNONE COMPOUNDS HAVING HETEROCYCLIC GROUPS AT THE 4-POSITIONS FROM 4-(BROMOACETYL)SYDNONES

New sydnone derivatives having heterocyclic substituents such as 4-thiazolyl, 3-thienyl, 2H-1,4-benzothiazin-3-yl, 2H-1,4-benzoxazin-3-yl, and 1,2-dihydro-3-quinoxalinyl groups at the 4-positions were prepared from 4-bromoacetyl-3-arylsydnones (1). Sydnone compounds substituted by a 1,2,3-triazol-4-yl group were prepared via new type phosphonium ylids derived from 1. Electroreduction of 1 was also attempted in order to prepare a syndnone derivatives having a furyl group.