Synthesis of alkylphosphonates with long hydrocarbon chains, chemical modifications and applications .2. Addition of HP(O)(OEt)(2) to alkenes and direct phosphonation of alkyl halides

Diester phosphonoalkyl monomers with long hydrocarbon chains were synthesized according to two routes: either by direct phosphonation of alkyl halides or by addition of HP(O)(OEt)(2) on an alkene. Direct phosphonation by a Michaelis Arbuzov reaction was performed on two halides, a chloride and a bromide, to compare their reactivity. The bromide method seemed to be the more efficient. Phosphonated monomers were synthesized in good yields by the addition of diethyl hydrogenophosphonate on alkenes. The second method led to a higher conversion than the former. We also silylated, with trimethylsilyl chloride, and hydrolysed these phosphonates into monoacid and diacid phosphonic compounds with long hydrocarbon chains. (C) 1996 Elsevier Science Ltd