A New Synthesis of 4H-1,4-Benzothiazine Derivatives Based on Ring Closure of EWG-Stabilized (2-Isocyanophenylthio)methyl Anions

Abstract

methylthiophenyl isocyanides were synthesized from 2-aminobenzenethiols and were shown to undergo ring closure to 2,4-disubstituted 4H-1,4-benzothiazine derivatives by deprotonation of the hydrogen adjacent to the sulfur atom with sodium hydride or potassium tert-butoxide, followed by trapping with various electrophiles.