Hydrochloric Acid → 4-Guanidinoimino-1-methanesulfonyl-3-methyl-6-(2-methylphenyl)-4,5,6,7-tetrahydroindole hydrochloride

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Reaction Steps

A mixture of 1-methanesulfonyl-3-methyl-6-(2-methylphenyl)-4,5,6,7-tetrahydroindol-4-one (0.20 g), aminoguanidine hydrochloride (0.073 g), concentrated hydrochloric acid (0.032 ml), water (0.032 ml) and ethanol (20 ml) was refluxed for 30 minutes. Under reduced pressure, the solvent was evaporated, and to the residue was added sodium hydrogen carbonate solution. The mixture was extracted with ethyl acetate, and the organic layer was purified with silica gel column chromatography (EtOAc/MeOH). To the resulting crystals was added 1N hydrochloric acid, and the mixture was concentrated. The residue was recrystallized from ethanol-ethyl acetate to give 4-guanidinoimino-1-methanesulfonyl-3-methyl-6-(2-methylphenyl)-4,5,6,7-tetrahydroindole hydrochloride (Compound 15) (0.16 g) as colorless crystals.

Provenance & Evidence