Acetic Anhydride → 2,2'-[[2-[(4-Bromo-3-methylphenyl)amino]-2-oxoethyl]imino]bisacetic acid

Temperatur

100 °C

A slurry of 9.56 g of nitrilotriacetic acid in 80 ml of dry pyridine (dried over molecular sieves) is heated to 55° C. Acetic anhydride (7.66 g) is added and the solution is heated to 100° C. After heating for 0.5 hour, the solution is cooled to 55° C. and 9.30 g of 4-bromo-3-methylaniline is added with a 5 ml pyridine rinse. The solution is heated at 100° C. for 1.0 hour. The reaction is cooled and rotary evaporated to a pasty solid which is dissolved in 120 ml of aqueous ammonium hydroxide (30 ml concentrated ammonium hydroxide/90 ml distilled water). The clear brown solution is extracted with two 100 ml portions of methylene chloride and neutralized to pH 3 with 35 ml of concentrated HCl. The white solid is filtered, washed with three 25 ml portions of cold distilled water, and dried under vacuum for 2.75 hours at 60° C. The crude product (12.9 g) is recrystallized from 360 ml of 50% ethanol to give 9.85 g of product, melting point 206.5°-209.0° C.

1. temperatureAfter heating for 0.5 hour
2. temperaturethe solution is cooled to 55° C.
3. washrinse
4. temperatureThe solution is heated at 100° C. for 1.0 hour
5. temperatureThe reaction is cooled
6. customrotary evaporated to a pasty solid which
7. dissolutionis dissolved in 120 ml of aqueous ammonium hydroxide (30 ml concentrated ammonium hydroxide/90 ml distilled water)
8. extractionThe clear brown solution is extracted with two 100 ml portions of methylene chloride and neutralized to pH 3 with 35 ml of concentrated HCl
9. filtrationThe white solid is filtered
10. washwashed with three 25 ml portions
11. distillationof cold distilled water
12. customdried under vacuum for 2.75 hours at 60° C
13. customThe crude product (12.9 g) is recrystallized from 360 ml of 50% ethanol

ORD-Eintrag

ord-6f74a6f587ca4248aaafdb136373b105

Quelldatensatz

uspto-grants-1983_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04418208