Patent ID: 6909010

Claim:
A process for preparing a P,P′-ester of a C 1 -C 10 alkylenebisphosphonic acid that comprises the steps of: (a) admixing one mole of C 1 -C 10 alkylenebis(phosphonic dichioride) with about two moles of an alcohol having a molecular weight of about 250 or less in the presence of a catalytic amount of an alpha-effect cyclic aromatic amine and at least two moles of a base in an aprotic solvent to form a first reaction mixture; (b) maintaining said first reaction mixture for a time period sufficient to form a C 1 -C 10 alkylenebis(chloro ester phosphonate) and a reaction mixture depleted of said alcohol; (c) admixing said formed C 1 -C 10 alkylenebis(chloro ester phosphonate) with an excess of a hydroxylated compound, YOH, that can be water, the same or different alcohol having a molecular weight of about 250 or less, or a primary C 1 -C 8 alcohol to form a second reaction mixture; and (d) maintaining said second reaction mixture for a time period sufficient to form a C 1 -C 10 alkylenebis(ester phosphonate) that is the corresponding partial ester, homoleptic tetraester or mixed tetraester, respectively.