As disclosed in W. Davies et al., Journal of the Chemical Society, 1951, pp. 2595-2598, it is known that 2-chloropropionitrile can be prepared by adding thionyl chloride to a mixture of lactonitrile and pyridine. To date, this has been the best method of producing 2-chloroacetonitriles on a large scale, even though it has led to the formation of a very thick slurry and has produced an isolated yield of only 50% after two distillations. It would obviously be desirable to find a way of improving this technique so as to improve processing and provide higher yields of 2-chloroacetonitriles.