EP 1165572 A1 20020102 - METHOD OF PREPARING N-PHOSPHONOMETHYL IMINODIACETIC ACID
Title (en)
METHOD OF PREPARING N-PHOSPHONOMETHYL IMINODIACETIC ACID
Title (de)
VERFAHREN ZUR HERSTELLUNG VON N-PHOSPHONOMETHYLIMINODIESSIGSÄURE
Title (fr)
PROCEDE DE PREPARATION D'ACIDE N-PHOSPHONO METHYLIMINO DIACETIQUE
Publication
Application
Priority
- DE 19914375 A 19990330
- EP 0002762 W 20000329
Abstract (en)
[origin: DE19914375A1] In the production of N-phosphonomethyliminodiacetic acid (PMIDA) by: (a) neutralizing an aqueous solution of the sodium salt of iminodiacetic acid (IDA) with a strong mineral acid (I) at 10-80 deg C; (b) separating IDA; (c) conversion to PMIDA by reaction with formaldehyde and phosphorous acid in aqueous solution in the presence of (I) at 100-150 deg C; and (d) separating PMIDA e.g. by filtration, the mother liquor from (d) is recycled to stage (a). Production of N-phosphonomethyliminodiacetic acid (PMIDA) involves: (a) neutralizing an aqueous solution of the sodium salt (Na2IDA) of iminodiacetic acid (IDA) with a strong mineral acid (I) at 10-80 deg C, (b) separating IDA from the solution, (c) conversion to PMIDA by reacting IDA with formaldehyde and phosphorous acid in aqueous solution in the presence of (I) at 100-150 deg C, optionally under a protective gas atmosphere and (d) separating PMIDA e.g. by filtration. The novelty is that the mother liquor from (d), with small amounts of PMIDA, reactants and by-products from stage (c), is recycled to stage (a).
IPC 1-7
IPC 8 full level
C07F 9/38 (2006.01)
CPC (source: EP)
C07F 9/3808 (2013.01)
Citation (search report)
See references of WO 0059915A1
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
DOCDB simple family (publication)
DE 19914375 A1 20001005; AR 023123 A1 20020904; AU 4540500 A 20001023; EP 1165572 A1 20020102; HK 1042903 A1 20020830; WO 0059915 A1 20001012
DOCDB simple family (application)
DE 19914375 A 19990330; AR P000101270 A 20000322; AU 4540500 A 20000329; EP 0002762 W 20000329; EP 00926772 A 20000329; HK 02104671 A 20020624