Hydrochloric Acid → 5-(4-Hydroxy-1-methyl-piperidin-4-ylmethyl)-3-methyl-1,5,6,7-tetrahydro-pyrrolo[3,2-c]pyridin-4-one

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Reaction Conditions

Reaction Steps

A stirred mixture of 2-{2-[(4-hydroxy-1-methyl-piperidin-4-ylmethyl)-amino]-ethyl}-4-methyl-1H-pyrrole-3-carboxylic acid ethyl ester (5.931 g, 18.36 mmol) in glycol (257 ml) was added with lithium hydroxide monohydrate (6.169 g, 147 mmol). The resulting mixture was heated to 135° C. for 4 hours. The mixture was added with cold water (250 ml), adjusted to pH from 14 to 12 with 2N hydrochloric acid in an ice-water bath. The mixture was extracted with a 10 to 1 solvent mixture of dichloromethane and methanol (200 ml×8). The combined organic extracts were concentrated under reduced pressure and the residue was purified by silica gel column chromatography with dichloromethane:methanol:ammonia (600:45:2) as eluents to give 5-(4-hydroxy-1-methyl-piperidin-4-ylmethyl)-3-methyl-1,5,6,7-tetrahydro-pyrrolo[3,2-c]pyridin-4-one (11.837 g) as a light brown oil which was used as such.

Provenance & Evidence