Samarium diiodide mediated regeneration of 1,2-benzenediamine and preparation of benzimidazolin-2-ones from 2,1,3-benzothiadiazoles

Abstract

On treatment with Sml3 in THF and in the presence of methanol, 2,1,3-benzothiadiazoles underwent reductive N-S bond cleavage leading to 1,2-benzenediamines in high yields. Without methanol but in the presence of triphosgene, benzimidazolin-2-ones were obtained in moderate yields under mild conditions.