E.i. Dupont De Nemours and Company

Walter John Cordes

George E Heinsohn

Julius Jakob Fuchs

John R Kosak

Charles T Blaisdell

John F Kook

Robert James Bassett

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.

Process for the preparation of methyl carbamates and thioimidates

Process for making methyl isocyanate comprising thermally dehydrochlorinating a solution of methyl carbamyl chloride in an aprotic nonpolar solvent, condensing the gases thereby formed at a temperature above the boiling point of methyl isocyanate so as to liquify at least part of said gases which are condensable at said temperature, removing HCl gas by condensing the remaining condensable gases at a temperature below the boiling point of methyl isocyanate, and separating methyl isocyanate from the condensate obtained in said first condensation step.

Methyl isocyanate process

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Wilmington, DE, United States of America

Walter John Cordes