Patent ID: 7227042

Claim:
A method of preparing 1-acetyl-1-chlorocyclopropane which comprises (a) providing 3,5-dichloro-2-pentanone; (b) providing a phase transfer catalyst selected from the group consisting of tetraalkylammonium halides and aryltrialkylammonium halides; (c) providing an aqueous solution of a base selected from the group consisting of bases whose conjugate acids have a pK a value in water of from about 8 to about 15; (d) admixing 3,5-dichloro-2-pentanone, the phase transfer catalyst, and the aqueous solution of the base at a temperature above room temperature in the absence of an organic solvent for a time sufficient to form 1-acetyl-1-chlorocyclopropane; and (e) separating the 1-acetyl-1-chlorocyclopropane.