Preferably, X is a halogen selected from the group consisting of chlorine, bromine, and iodine with chlorine being preferred, R1 is an alkyl, alkenyl, or aryl group having from 1 to 18 carbon atoms and R2 and R3 are the same or different halogens, or alkyl, alkenyl, or aryl groups having from 1 to 18 carbon atoms.