2-Substituted 5,6-Dihydro-1,3-thiazines from Nitriles and Thiocyanates: a Modification of Meyers's Method

Abstract

The thiazines (4)–(13) were prepared in high yields from corresponding nitriles or thiocyanates and 4-mercapto-2-methylbutan-2-ol (2) in methanesulfonic acid. The use of thiocyanates for preparing 2-sulfur-substituted thiazines is reported herein apparently for the first time. Thiazines (9) and (10) were observed to exhibit imine–enamine tautomerization by ¹H n.m.r. spectroscopy.