Water → HCID 20290071, compound

Participants

Reaction Steps

To a 0.02 mole portion of the disodium salt of N-phosphonomethylglycine, prepared as described in previous examples, there is added 3.2 grams (0.01 mole) of 3,3',4,4'-benzophenonetetracarboxylic dianhydride. A pH of about 8 is maintained with periodic additions of alkali, and further anhydride, in 3.2 grams and 1.0 gram portions, are added to complete the reaction. The reaction mixture is diluted with water and passed through a column of ion exchange resin in the acid form. The second and third 20 ml. cuts are combined and dried to yield 4-(3',4-dicarboxybenzoyl)-N-carboxymethyl-N-(phosphonomethyl)phthalamic acid (in the monohydrate form) as a tan glass. Elemental analysis gives 44.18% carbon, 3.47% hydrogen, 2.77% nitrogen and 6.12% phosphorus as against calculated values of 45.55%, 3.44%, 2.66% and 5.87% for C20H16NO13P.H2O. ##STR22##

Provenance & Evidence