Process for the continuous production of 2-phosphono-butane-1,2,4-tricarboxylic acid and alkali metal salts thereof

Abstract From the Canadian patent

A PROCESS FOR THE CONTINUOUS PRODUCTION OF 2-PHOSPHONO- TANE-1,2,4-TRICARBOXYLIC ACID AND ALKALI METAL SALTS THEREOF, ABSTRACT OF THE DISCLOSURE, This invention relates to an improved process for the continuous production of 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC) and alkali metal salts thereof, in which dialkylphosphite and ethene-1,2-dicarboxylic acid dialkyl ester are reacted in the, presence of a basic catalyst to form phosphonosuccinic acid tetraalkyl ester, the ester thus obtained is directly reacted with alkyl-acrylate, in the presence of an alkaline catalyst and the reaction product thus obtained is directly hydrolyzed to PBTC or alkali metal salts thereof.