New routes to diethyl 1-fluoromethylphosphonocarboxylates and diethyl 1-fluoromethylphosphonocarboxylic acid

Diethyl 1-fluoromethylphosphonocarboxylic esters 4, bearing a variety of ester groups (alkyl, aryl), have been conveniently prepared in a one-pot process, by reaction of chloroformates with 1-lithio-1-fluoro-1-(trimethylsilyl)methylphosphonate 2 derived from 1,1-dibromo-1-fluoromethylphosphonate 1. The overall yields generally range from 80 to 91 %. Reaction of 2 with CO 2 leads to a novel efficient synthesis of diethyl 1-fluoromethylphosphonocarboxylic acid 7 in 86% yield. Graphic