Preparation of N-chlorothio(methyl)carbamoyl halides

A process for preparing a N-chlorothio(methyl)carbamoyl halide which comprises (a) reacting N-methylcarbamoyl halide with an excess of sulfur dichloride in the presence of a tertiary organic base to form a mixture containing N-chlorothio(methyl)carbamoyl halide and sulfur monochloride;

• (b) chlorinating the mixture obtained in (a) to obtain a product containing N-chlorothio(methyl)carbamoyl halide and sulfur dichloride and (c) subjecting the product obtained in (b) to distillation.