Method for the production of substituted or unsubstituted chloromethyl cyclopropane and bromomethyl cyclopropane

A method for the production of a haloaklane selected from the group consisting of chloromethyl cyclopropane and bromomethyl cyclopropane, comprising the steps of:

• reacting a hydroxymethyl cyclopropane of the formula ##STR5## where R is H, or one or two R groups are independently alkyl of from 1 to 10 carbon atoms or phenyl, with a methane sulfonic acid halide selected from the group consisting of methane sulfonic acid chloride and methane sulfonic acid bromide in the presence of a trialkylamine at a temperature of from -20.degree. C. to +30.degree. C. for a length of time of from 1 to 30 hours, to provide a reaction mixture containing an intermediate mesylate,
• heating said reaction mixture to a temperature of from +40.degree. to +80.degree. C., or to reflux temperature, without isolating said intermediate mesylate, and
• isolating said haloalkane selected from the group consisting of chloromethyl cyclopropane and said bromomethyl cyclopropane, said haloalkane selected from the group consisting of chloromethyl cyclopropane and bromomethyl cyclopropane having a degree of purity of above 85%.