Difluoromethylenediphosphonate: a convenient, scalable, and high-yielding synthesis.

[reaction: see text] Since the first disclosure of difluoromethylenediphosphonate, 2, almost 40 years ago, interest in this compound has flourished in several research areas. In this paper, we present a convenient, high-yielding (99% overall) method for the preparation of milligram to multigram quantities of 2 (as the bis(tributylammonium salt, 2b) in a solid form that is easy to handle.