METHOD FOR PREPARING CRYSTALLINE NITRILOTRIMETHYLPHOSPHONIC ACID DISODIUM SALT MONOHYDRATE Russian patent published in 2007 - IPC C07F9/38 

FIELD: chemical technology.

SUBSTANCE: invention relates to technology for synthesis of crystalline nitrilotrimethylphosphonic acid sodium salts. For synthesis of nitrilotrimethylphosphonic acid disodium salt monohydrate the method involves preliminary synthesis of nitrilotrimethylphosphonic acid by interaction of phosphorus trichloride, formaldehyde and ammonia or its derivative followed by neutralization with sodium hydroxide in the content in the reaction mass 46-54 wt.-% of nitrilotrimethylphosphonic acid and 6.0-16.0 wt.-% of hydrogen chloride up to pH value 2.5-4.5, and isolation of the end compound by crystallization. The mass part of the main substance in synthesized product is 88-95%, the content of chloride ions is 1.2-2.0%, yield is 50-60% as measured for PCl₃. Synthesized compound is recommended for using as chelate compounds as a component of detergents, anti-rheological additive in drilling solutions, plasticizing agents for building concretes, in wine-making industry, as inhibitors of salt depositions in heat and power engineering and others fields.

EFFECT: improved method of synthesis.

2 tbl, 12 ex