Methylamine → (2R)-2-{(3R,6R)-3-(2,3-Dihydro-1H-inden-2-yl)-6-[(1S)-1-methylpropyl]-2,5-dioxo-1-piperazinyl}-2-(2,6-dimethyl-3-pyridinyl)-N-methylethanamide

Participants

Reaction Steps

2-{(3R,6R)-3-(2,3-dihydro-1H-inden-2-yl)-6-[(1S)-1-methylpropyl]-2,5-dioxo-1-piperazinyl}-2-(2,6-dimethyl-3-pyridinyl)-N-(2-hydroxyphenyl)acetamide (intermediate 2) (0.400 g, 0.74 mmol) and 1,1′-carbonyldiimidazole (0.192 g, 1.18 mmol) in dry dichloromethane (10 mL) were stirred at room temperature under N2 for 7 hrs. The mixture was treated with a 2M solution of methylamine in tetrahydrofuran (1.849 mL, 3.70 mmol) and left to stand overnight at room temperature. The solvents were blown down under N2 and the residue was purified on a Redisep silica column (35 g) eluted with 0-10% methanol in ethyl acetate followed by further purification on a Kromasil KR100-10-C18 reverse-phase column eluted with aqueous acetonitrile (20-45% MeCN) containing 0.1% formic acid. This gave the title compound as a white lyophilisate (30%) after freeze-drying from 1,4-dioxane.

Provenance & Evidence