Facile Syntheses of Pyrido[2,1-c]-1,4-thiazine Derivatives

Abstract

Alkaline treatment of 1-C7-(cyano-or acylmethylthio).vinyllpyridinium bromides gave smoothly new heterocyclic compounds, 1-cyano-or 1-acyl-1,9a-dihydropyridoL2,l-&I-l,4-thiazine derivatives. 2In our preceding paper , we described a preparative method for 3-acyl or 3 -( a c y l t h i o ) p y r a z o l o C 1 , 5 -s l p y r i d l n e derivatives from rhe reactions of 1-[(acyl-