The Preparation of 2-Alkoxy-1,3,2-oxazaphospholidines and Some Reactions

Abstract

The preparation of 2-alkoxy-1,3,2-oxazaphospholidines and some reactions will be described. 2-Alkoxy-1,3,2-oxazaphospholidines were prepared either from ethyl phosphorodichloridite and aminoethanols or, more conveniently, from tris[diethylamino]phosphite, aminoethanols and alcohols. 2-Alkoxy-1,3,2-oxazaphospholidines reacted easily with alcohols or p-toluenesulfonic acid monohydrate to give dialkyl aminoethyl phosphites or alkyl aminoethyl phosphite by the ring-opening at the P–N linkage of the phospholidines. It was oxidized by means of sulfur or nitrogen tetroxide to give 2-thione or 2-one in high yields. Further, it was found that it reacted with ethyl isocyanate to form 1 : 1 adducts. The structure of the adducts was confirmed, by a study of its chemical transformations, to be a seven-membered cyclic compound. It also reacted with carbon dioxide at about 120°C to yield the phosphorous-containing polyamide.