• Journal of the Korean Chemical Society
• /
• v.46 no.4
• /
• pp.330-336
• /
• 2002

For the purpose of development of new agrochemical fungicide of ${\alpha},{\beta}-unsaturated$ carboxanilide series a synthesis of 4-acetyl-3-methyl-N-phenyl-1,4-thiazine-2-carboxamide (6) is described. Pummerer reaction of sulfoxide 7 obtained by sulfoxidation of dihydro-1,4-thiazine methyl ester 11 gave ${\alpha}-acetoxy$ dihydro-1,4-thiazine 10a. Under the same reaction conditions, dihydro-1,4-thiazine carboxanilide sulfoxide 14 was converted to acetoxymethyl dihydro-1,4-thiazine 18 through vinylogous Pummerer reaction involving carboxanilide of sulfonium ion through intermediate 15.1,4-Thiazine carboxanilide 6 was synthesized from the treatment of ${\alpha}-acetoxy$ dihydro-1,4-thiazine 10a with acid cat-alyst followed by hydrolysis and then the reaction with aniline.