Among the suitable phase transfer catalysts which can be utilized are catalysts of the formula (R5)4Q+X, where R5 is independently at each occurrence an alkyl group having 1 to 10 carbons, Q is a nitrogen or phosphorus atom, and X is a halogen atom, or an ???OR6 group, where R6 is selected from a hydrogen, an alkyl group having 1 to 8 carbon atoms and an aryl group having 6 to 18 carbon atoms.