Amino-alkylene-phosphonic acids prepn. - by saponifying the corresponding mono-methyl ester using heat only

摘要

The novel prepn. comprises (a) reacting a mixt. of ammonia or an organic prim. or sec. amine, a carbonyl cpd. and a phosphorous dialkyl ester to form the correps. monoalkyl ester which is then (b) saponified. Dimethyl phosphite is used to obtain the corresp. monomethyl ester. Both (a) and (b) are effected by heating, (b) is effected without using a catalyst, at 150-180 degrees C. The amino-methylene phosphonic acids are obtained completely free from HCl.