Perchloric Acid → Methyl 5-[(4-methoxyphenyl)(methylimino)methyl]-1,4-dimethyl-1H-pyrrole-2-acetate Perchlorate

Participants

Reaction Conditions

Reaction Steps

N-Methyl 4-methoxybenzimidoyl chloride (6.67 g, 36.4 mmole) was placed in a dry 50 ml round bottom flask and treated with alcohol free chloroform (13 ml) and chlorosulfonic acid (0.42 g, 3.6 mmole). The reaction was blanketed with nitrogen and stirred while methyl 1,4-dimethyl-1H-pyrrole-2-acetate (6.03 g., 36.1 mmole) was added dropwise over a period of about five minutes. The reaction was stirred overnight, then heated at 40° C. for two hours. The reaction was quenched with saturated aqueous sodium bicarbonate. The phases were separated, and the organic phase was washed with saturated aqueous sodium bicarbonate and water, then dried over sodium sulfate. The chloroform was removed under reduced pressure to yield a red viscous liquid. The crude product was dissolved in absolute ethanol and treated with 70% perchloric acid (5.7 g, 40 mmole). The solution was cooled and treated with ether to induce crystallization. The yellow solid was isolated by filtration and washed with cold ethanol to yield 10.5 g (64%) of the title compound, m.p. 123°-129° C. (dec).

Provenance & Evidence