Synthesis method of (S)-1-(2-chloracetyl)pyrrolidine-2-formonitrile

The invention relates to a synthesis method of (S)-1-(2-chloracetyl)pyrrolidine-2-formonitrile. The method comprises the following steps: mixing (S)-N-chloracetyl-2-carbamoylpyrrolidine and chloroacetyl chloride in a reactor, carrying out dehydration reaction to obtain a target product which is (S)-1-(2-chloracetyl)pyrrolidine-2-formonitrile. The invention also relates to a method for synthesizing the target product which is (S)-1-(2-chloracetyl)pyrrolidine-2-formonitrile by taking L-prolinamide as raw material. The synthesis method has the advantages of simple operation, high efficiency, high yield, high purity and low cost, and is safe and environmentally friendly.