Formation of α-mono- and αα′-di-methyl or -phenyl derivatives of tosylhydrazones through an in situ sequence by treatment with lithium dimethyl- or diphenyl-cuprate

Abstract

The reaction of a tosylhydrazone with tri-N-methylanilinium perbromide in 1 : 1 or 1 : 2 ratio, followed by in situ treatment with lithium dimethyl- or diphenyl-cuprate, gives α-mono-methyl or -phenyl or αα′-di-methyl or -phenyl derivatives. The generality, limitations, and usefulness of this process are discussed.