Hexamethylphosphoramide

Growing interest is being shown in the role of the solvent (particularly polar solvents) in chemical reactions [1–4] . The most remarkable polar aprotic solvent appears to us to be the hexamethylated triamide of orthophosphoric acid, OP(N(CH 3 ) 2 ) 3 , which is known as hexamethylphosphoramide or tris(dimethylamino)phosphine oxide. Hexamethylphosphoramide [5–7] has recently been studied with respect to its solvent properties for gases [5] , for many organic and inorganic salts [7] , and for polymers [5] , as well as its use as a polymerization co‐catalyst. However, these aspects are not considered in the present paper, which deals with the physical and chemical properties of hexamethylphosphoramide, and in particular with its use as a reaction medium. Our own work on hexamethylphosphoramide began in 1961, and until then very little work had been done on this compound. Even in a paper published by Parker [1b] in 1965, very little reference is made to hexamethylphosphoramide.