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

Abstract

2-Cyano(phenylsulfinyl-, p-nitrophenyl-, or o-nitrophen­yl-)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.

Key words

benzothiazine - carbanion - heterocycle - isocyanide - ring closure

References

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