The synthesis and reactivity of alkyl-aminosubstitutedmethylenediphosphonates

Reactions of diethyl phosphite with Vilsmeier reagents, RCONR1R2/POCl3, afforded various alkylaminosubstitutedmethylenediphosphonates in acceptable yields, which (R = H) were then reacted with aldehydes under the conditions of the Wittig–Horner reaction to furnish vinylphosphonates, and which (R = H) underwent alkylation with alkyl halides to give alkylaminosubstitutedmethylenediposphonates 8. (Z)-Vinylphosphonates could be converted to (E)-isomers in refluxing ethyl acetate.© 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 271–276, 1999