Synthesis of isocyanates from nitroalkanes

摘要

A process for the preparation of aromatic isocyanates from nitroalkanes. A nitromethyl aromatic compound of the general formula: wherein R and R1 represent hydrogen, halogen, a C1-C5 alkyl radical, a C1-C4 alkoxy radical, nitro, isocyanato, an alkoxycarbonylamino, or nitromethyl radical, with R and R1 being the same or different, is heated in the presence of an effective amount of a Lewis acid or Bronsted acid substance to effect a dehydrogenation-isomerization reaction to yield an aromatic isocyanate of the general formula: The product of the reaction may be recovered as the aromatic isocyanate or the alcohol adduct, a carbamate.