SU525666A1 - Bis- / carboxymethyl / -aminomethyl derivatives of phenol carboxylic acids as masking agents - Google Patents

Description

complexes with metals in the direction of high pH values, which in turn ensured a high masking ability with respect to cations and improved the selectivity of new compounds. Thus, in the presence of compounds I – IV, precipitation of metal hydroxides is observed at higher pH values as compared with the previously known complexones: cobalt and copper are masked with Dy pH 11 (for o-hydroxyphenyliminodiacetic acid pH 8–9), iron is masked to pH 10.5–11 (for 0-, p-hydroxyphenyliminodiacetic acids pH 5-) magnesium is masked to pH 14 (for 0-, M-, n-oxyphenylaminodiacetic acids pH 10-11) The selectivity of the new compounds appears in that, for example, cobalt and copper are masked, unlike nickel, which falls in the form poorly soluble complex at pH 6-8; cadmium and zinc are aspirated, in contrast to lead, also in falling in the form of a little soluble complex at pH 4.5-6; heavy rare-earth elements (holmium-lutetium) from light rare-earth elements (lanthanum-dysprosium, precipitated as poorly soluble complexes at pH 4.5-6. Bis- (carboxymethyl) aminomethyl derivatives of the above general formula are obtained in various ways depending on the reactivity of the initial Phenolcarboxylic acids. Compounds II and HI are obtained by the Mannich reaction by the condensation of iminodiacetic acid, formaldehyde, and 2,4-dioxybenzoic acid (compound II) or 4-hydroxyben OAK acid (compound III). Since 2-hydroxybenzo acid and its sulfonolalogue were found with low-active C-components in the Mannich condensation, compounds I and IV were obtained by interaction of the corresponding chloromethyl benzoic acids with iminodioxenic acid (3-chloro-methyl-2-hydroxybenzoic acid for compound I and 3-chloromethyl-2-) xi-5-sulfobenzoic acid for compound IV). Example 1. 3-bis (carboxymethyl) aminomethyl-2-hydroxybenzoic acid (compound I). A solution of hydrogen chloride at 70 ° C for 12 hours is passed through a solution of 13.8 g of 2-hydroxybenzoic acid and 3g paraform in 150 ml of dioxane. The solvent is distilled off, the residue is extracted with hot benzene. The precipitate of the extract extract is filtered and washed with benzene. After recrystallization from a mixture of azatoncyclohexane, 5.1 g of 3-chloromethyl-2-hydroxybenzoic acid are obtained (30% of theory). Found,%: C 51.9i H 3.8 and 3.9; Cei8.6 and 18.8; C BUT C1 Calculated,%: C 51.5 N 3.8; C1 19.00. IR range:. 680 cm 760 cm which can be attributed to the replacement of 1,2,3. To 9.3 g of 3-chloromethyl-2-hydroxybenzoic acid in 100 ml of dimethylformamide (DMFL) were added 4 g of potassium carbonate and 6.7 g of iminodiacetic acid in 1OO ml DMFA. The mixture is heated at 80-85 ° C for 20 hours, cooled to 10-15 ° C and filtered from an inorganic precipitate, and complexone is precipitated from the filtrate by adding 700 ml of isopropyl alcohol. The precipitate is filtered off, rinsed with isopropyl alcohol and dried in a vacuum desiccator. Obtain 10 g (72% of theory.) Found.%: C 5O, 7 and 50.8; H 4.9 and 4.8: N 5.1 and 5.2. C, aH, 3NO, Calculated,%: C 50.8; H 4.6; N4.9. Example 2. H-bis (carboxymethyl) aminomethyl-2, 4-dioxybenzoic acid (compound II). To 15.4 g of 2,4-dioxybenzoic acid in ZOO ml of acetic acid was added 14.6 g of iminodiacetic acid, previously neutralized with 30% sodium hydroxide to pH 7-8. The solution is cooled to 10–15 C n at this temperature, 10.3 g are added dropwise with 35% formaldehyde. Through. 40 minutes after the completion of the dripping, the complexone precipitate begins to precipitate. The mixture is heated to 50 ° C and kept at this temperature for 3 hours, cooled, the sediment of the complexone is filtered off, washed first with water until a negative reaction to acetation, then with ethyl alcohol and dried at 50 ° C in a drying cabinet. Get 23.9 g (57% of theory). Found,%: C 48.4 and 48.3; H 4.5 and 4.6; N 4,6 and 4,7 C, H, 3NOg Calculated,%: C 48.2; H 4.4; N 4.7. MK-cneKTp: v) j.740 804 cm, which can be attributed to the replacement of 1,2,3. PRI me R 3. 3-bis (carboxyme 1) aminomethyl-4-hydroxybenzoic acid (compound III). 14.6 g of iminodiacetic acid, also neutralized with 20% sodium hydroxide to pH 7-8, are added to 13.8 g of 4-hydroxybenzoic acid neutralized with 20% sodium hydroxide and pH 7-8 and the reaction solution is cooled to S- 7 C. At this temperature and stirring, 10.3 g of a 35% formaldehyde solution are added dropwise for 30 minutes, aging is carried out for 1 hour at 5-7 ° C; 3 hours and 55-QO C. At the end of the exposure

the solution is cooled to 5-7 ° C and acidified with hydrochloric acid to pH 1.5. The precipitated complexone is filtered and washed with 6O% aqueous ethanol until there are no chlorine ions and dried at 50 ° C. 11.5 g are obtained (35% of theory).

Found,%: C 50.7 and 50.8 H 4.8 and 4.8; N 5.2: 5.1.

C, j, H, jN07

Calculated with 1%: C 50.9; H 4.6; N4.9.

Example 4. 3-bis (carboxymethyl l) aminomethyl-2-hydroxy-5-sulfobenzoic acid (compound IV). After 10.9 g of 2-hydroxy-5-sulfobenoic acid in 150 ml of concentrated hydrochloric acid, 5 ml of concentrated sulfuric acid and 5 g of 35% formaldehyde, an intensive current of hydrogen chloride is passed over 4 hours at aO-ZO C and 10 -12 h at 50 ° C. 3-chloromethyl-2-hydroxybenzoic acid was isolated by precipitating 1 l of isopropyl alcohol from the reaction solution, washed with isopronyl alcohol, and dried at. Get It), 4 g (40% of theory).

Found,%: C 36.2 and 36.4; H 2.9 and 2.8; C1-13.3 and 13.4

C h ceo.s.

N1,%: C 36.0; H 2.6; C1 13.3.

Logarithms of the stability constants of metal complexes

To 5.4 g of 3-chloromethyl-2-hydroxy-5-sulfobenzoic acid 1.6 g of potassium carbonate in 75 ml of DMF is added a solution of 2.7 g of iminodiacetic acid in 1OO ml of DMF and heated under stirring at 80-85 ° C within 20 hours After cooling to 20 ° C, the reaction mass is filtered off from an inorganic precipitate and complexone is precipitated from the filter by adding 500 ml of isopropyl alcohol. Inserted white precipitate is filtered off, washed with 50 ml of isopropyl alcohol and dried in a vacuum desiccator.

Obtain 3.8 g (43% of theory).

Found,%: C 40.0 and 39.9j H 3.7 and 3.8; N 4.0 and 4.2.

C, AN, ZMO, O5

Calculated,%: C 39.7; H 3.6; N 3.6. The study of complex-forming properties was carried out by potentiometric method on a pH-340 potentiometer with glass and calomel electrodes. From the curves of potentiometric titration, the dissociation constants of new complexons and the stability constants of the metal complexonates formed by them were calculated. Titration was carried out in a thermostated cell at 25 ° C in a stream of purified nitrogen ..