Abstract
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.
새로운 ${\alpha},{\beta}$-불포화Carboxanilide계열의 살균제를 개발을 목적으로 4-acetyl-3-methyl-N-phenyl-1,4-thiazine-2-Carboxamide(6)의 합성에 대하여 기술하였다. Dihydro-1,4-thiazine methyl ester 11을 산화하여 생성된 sulfoxide 7을 Pummerer 반응하여 $\alpha$-acetoxy dihydro-1,4-thiazine 10a를 얻었다. 반며에 Dihydro-1,4-thiazine Carboxanilide sulfoxide14는 동일한 반응조건 하에서 중간체 sulfonium ion의 carboxanilide기가 관여한 vinylogous Pummerer 반응의 전위에 의하여 중간체를 15를 통하여 acetoxymethyl dihydro-1,4-thiazine 18이 생성되었다. 1,4-Thiazine carboxanilide 6은 $\alpha$-acetoxy dihydro-1,4-thiazine 10a를 산촉매로 처리한 다음 생성된 21a를 가수분해하고 아닐린과 결합하여 합성하였다
