New highly efficient method for the synthesis of tert-alkyl nitroso compounds

摘要

The syntheses of tert-alkyl nitroso compounds RCH2CMe2N=O from commercially available tert-alkyl amines RCH2CMe2NH2, proceed cleanly via the intermediacy of the benzoyl derivatives RCH2CMe2NHOC(O)Ph and the corresponding hydroxylamines RCH2CMe2NHOH. Since the intermediates require no purification in the course of the transformations, the overall yields of the isolated crystalline nitroso dimers (75-80% for R = H, 75% for R = Me and 66% for R = Me3C) are based on the corresponding amine precursors. In the latter case (R = Me3C), significant steric demands and hydrophobicity of Me3CCH2CMe2 group necessitate the application of more efficient reagents and conditions on the debenzoylation and oxidation steps. The syntheses are perfectly suitable for scale-up and were Successfully performed Oil Lip to 500-mmol scale.