Preparation of haloesters from dienes

Claim 1

A process for the preparation of 4-halo-3-methylbut-2-enyl lower fatty acid esters from isoprene comprising the steps of; a. halogenating isoprene in the presence of at least about 0.05 mols per mol of isoprene of a dipolar aprotic solvent selected from the group consisting of N,N-dimethylformamide, N,N-dimethylacetamide, acetamide, N-methylpyrrolidine, hexamethyl phosphoramide, and dimethylsulfoxide under halogenation conditions with elemental halogen to produce a reaction mixture a predominant portion of which is 1,4-dihalo-2-methyl-2-butene; b. esterifying the reaction mixture of step (a) in an esterification reaction under esterification reaction conditions with an alkali metal salt of a lower fatty acid, the esterification reaction being carried out in the presence of a catalyst consisting essentially of an amine or phosphine at a temperature in the range of about -100° to 300° C, the amount of alkali metal salt employed being the amount stoichiometrically necessary to replace the halogen ion in the 1-position with the anion of said alkali metal salt to produce a product mixture of which a predominant portion is the desired 4-halo-3-methylbut-2-enyl lower fatty acid ester.