| abstract |
Preparation of dialkyl phosphinic acids and their salts comprises: a) reacting elementary yellow phosphorus with alkylation agents in a base to give a mixture of metal(salt)s of alkyl phosphorous, phosphorous and hypophosphorous acids; (b) esterifying the mixture; (c) isolating the alkyl phosphonic acid ester; (d) producing the dialkyl phosphinic acid esters by radical-inert reaction with olefins; and (e) converting to free acids or group IA, IIA, IIIA, IVA, IIB, IVB, VIIB or VIIB metal salts. |