Organophosphorus compounds. V. Dialkyl alkylphosphonates from alkyl halides and sodium dialkyl phosphonates in liquid ammonia

Abstract

Liquid ammonia is a useful solvent for the reaction of various alkyl halides with sodium dialkyl phosphonates. In this medium ethyl bromide, amyl bromide, octyl bromide, ally1 chloride, and benzyl chloride give the corresponding dialkyl alkylphosphonates in good yield. In other cases, alternative products are formed. Thus sodium diethyl phosphonate reacts with carbon tetrachloride or chloroform in liquid ammonia to give diethyl phosphoramidate; dibromomethane gives diethyl methylphosphonate and an equivalent quantity of diethyl phosphoramidate. p-Nitrobenzyl bromide gives mainly 1,2-di(p-nitrophenyl)ethane, 1-bromooct-1-yne is reduced to oct-1-yne, and 3-bromoprop-1-yne gives mainly propyne together with some diethyl prop-l- ynylphosphonate.