Process for the preparation of methyl carbamates and thioimidates

摘要

A continuous, close-coupled method for making N-methyl carbamate pesticides which comprises contacting the methyl isocyanate in a vapor phase mixture containing methyl isocyanate and water with a selected oxime or phenol, said mixture being the reaction product formed by oxidizing monomethylformamide. An optional intermediate step for preparing the methyl isocyanate/water vapor phase reaction mixture for contact with the oxime or phenol is to remove therefrom a portion of the water without liquefying the methyl isocyanate by cooling the mixture to a temperature below the dew point of water but above the dew point of the methyl isocyanate.