N-phosphonomethylamines are produced by reaction of an amine substrate with a halomethylphosphonic acid or salt thereof, a hydroxymethylphosphonic acid or salt thereof, or a dehydrated self-ester dimer, trimer or oligomer of hydroxymethylphosphonic acid. Among the products that may be prepared according to the process are N-phosphonomethylaminocarboxylic acids such as (e.g.) glyphosate, N-phosphonomethylaminoalkanols such as (e.g.) hydroxyethlaminomethylphosphonic acid, and N-acylaminomethylphosphonic acids such as (e.g.) N-carbamylaminomethylphosphonic acid. Certain reactions are conducted with a substantial excess of amine reactant in order to drive the conversion while avoiding excessive formation of bis(N-phosphonomethyl)amine by-products. Other reactions use a secondary amine substrate (such as iminodiacetic acid) and can be conducted at substantial equimolar ratios of halomethylaminomethylphosphonic acid or hydroxyaminomethylphosphonic acid to secondary amine reactant without significant formation of bis(phosphonomethyl)amine by-products. Further disclosed is a process for the preparation of hydroxymethylphosphonic acid self-ester dimers, trimers and oligomers by azeotropic dehydration.
N-
磷酸甲基胺是通过胺底物与卤
甲基膦酸或其盐、
羟甲基膦酸或其盐,或
羟甲基膦酸的脱
水自酯二聚体、三聚体或寡聚体反应而制备的。根据该过程可制备的产品包括N-
磷酸甲基
氨基
羧酸,如
草甘膦,N-
磷酸甲基
氨基烷醇,如羟乙
氨基
甲基膦酸,以及N-酰
氨基
甲基膦酸,如N-
氨基
甲基膦酸。为了推动转化并避免过多形成双(N-
磷酸甲基)胺副产物,某些反应中使用大量过量的胺试剂。其他反应使用二次胺底物(如
亚胺二
乙酸)并可在相当量的卤甲基
氨甲膦酸或羟
氨甲膦酸与二次胺试剂的摩尔比下进行,而不会显著形成双(
磷酸甲基)胺副产物。还公开了通过共沸脱
水制备
羟甲基膦酸自酯二聚体、三聚体和寡聚体的方法。