A Simple Strategy for the Preparation of 6-Substituted 3H-Benzoxazol-2-ones and 3H-Benzothiazol-2-ones

Abstract

The double metallation of 6-bromo-3H-benzothiazol-2-one and 6-bromo-3H-benzoxazol-2-one with methyl magnesium bromide and alkyllithium bases is described. Alkylation with a variety of electrophiles occurs at the 6-position of the heterocycles in good yields.

Keywords:

• Benzothiazolidinone
• benzoxazolidinone
• metallation

Notes

^a tert-Butyl lithium was used instead of sec-butyl lithium for step ii, Scheme 1.