Perchloric Acid → Methyl 1,4-Dimethyl-5-[(methylimino)phenylmethyl]-1H-pyrrole-2-acetate Perchlorate

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Reaction Steps

Methyl 1,4-dimethyl-1H-pyrrole-2-acetate (1.66 g, 10 mmole) was placed in a 25 ml round bottom flask and treated with alcohol free chloroform (2 ml) and N-methyl benzimidoyl chloride (1.78 g, 12 mmole). The solution was treated with several drops of ethereal hydrogen chloride--mild exotherm. The reaction was protected with a calcium chloride drying tube and stirred at room temperature for about four hours. The reaction was diluted with chloroform, quenched into saturated sodium bicarbonate, washed with brine, dried over sodium sulfate, filtered and concentrated. The viscous residue was dissolved in absolute ethanol (6 ml) and treated with 70% perchloric acid (1.42 g, 10 mmole). The resulting crystalline solid was isolated by filtration and washed with ethanol/ether (1 to 3 by volume) and air dried to yield 2.39 g (62%) of the title compound as a bright yellow solid, m.p. 149°-150° C.

Provenance & Evidence