Summary: Copper (1) halide catalyzed acylation of [(di-ethoxyphosphinyl) difluoromethyl] zinc bromide with ethyl chloroformate provides a safe, easily scaled up preparation of ethyl difluoro (diethoxyphosphiny1) acetate from readily available precursors. Silyation of this ester, followed by hydrolysis, gives difluorophosphonoacetic acid.
