Organophosphorus esters—IV : Novel approach to monoalkyl hydrogen phosphites

Tetramethylammonium t-butyl hydrogen phosphite (2), readily available from the reaction between di-t-butyl phosphite and aqueous tetramethylammonium hydroxide, was found to be a convenient phosphorylating agent for organic halides. It reacts easily with alkyl iodides and some alkyl bromides in boiling acetone affording the corresponding alkyl t-butyl phosphites (3). On treatment with trifluoroacetic acid at room temperature these compounds can be readily converted into monoalkyl hydrogen phosphites (1), isolated and characterized as S-p-chlorobenzylthiouronium derivatives (4).