Hydrochloric Acid → HCID 20515464, compound

Participants

Reaction Conditions

Reaction Steps

15 ml of concentrated hydrochloric acid are added to the solution obtained in Example 4, which contains 49.2 g (0.19 mole ) of 3-[(2-aminophenyl)amino]-1,4,5-trimethyl-1H-pyrrole-2-carboxylic acid, and the mixture is heated to an internal temperature of 140° C. for 12 hours. During this heating, the water formed is continuously distilled off. For working up the mixture, as much of the solvent as possible is distilled off on a rotary evaporator under a water-pump vacuum. The residue is taken up in 100 ml of water, and the mixture is adjusted to pH 2, at 80° C., with concentrated hydrochloric acid. The mixture is cooled to 0° C., with stirring. The precipitate formed is filtered off. The filtrate is extracted 3 times with 50 ml of ethyl acetate each time. The combined filtrates are dried with sodium sulfate and concentrated, and the residue is again taken up in 50 ml of water. The resulting mixture is adjusted to pH 2, at 80° C., with concentrated hydrochloric acid. After the mixture has been cooled to 0° C. in an ice-bath, it is filtered. The combined residues on the filter are washed with water and recrystallized from ethyl acetate.

Provenance & Evidence