Preparation of diphenylmethane dicarbamates and polymethylene polyphenyl carbamates with Lewis acid catalysts intercalated in graphite.

摘要

Diphenylmethane dicarbamates and polymethylene polyphenyl carbamate homologs and derivatives of these compounds are produced by the condensation of N-aryl carbamic acid esters, such as ethylphenylcarbamate, with a carbonyl compound selected from formaldehyde, para-formaldehyde or trioxane at a temperature of between about ambient and 170°C. in the presence of a Lewis acid intercalated in graphite and optionally in the presence of an inert solvent.