Potassium Carbonate → 10-Chloro-7-(1-ethylpropyl)-1-(6-methoxy-4-methylpyridin-3-yl)-2,3,4,5-tetrahydro-1H-[1,3]diazepino[1,2-a]benzimidazole

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Reaction Steps

To a solution of 4-{4-chloro-7-(1-ethylpropyl)-2-[(6-methoxy-4-methylpyridin-3-yl)amino]-1H-benzimidazol-1-yl}butan-1-ol (100 mg, 0.23 mmol) in pyridine (2 mL) was added methanesulfonyl chloride (0.090 mL, 1.16 mmol) dropwise at 0° C. The mixture was warmed to room temperature and stirred for 40 hr. Aqueous sodium bicarbonate was added and the mixture was extracted with ethyl acetate. Organic layer was washed with brine, dried over magnesium sulfate and concentrated in vacuo. The resulting crude mesylate was dissolved in N,N-dimethylformamide (4 mL) and potassium carbonate (160 mg, 1.16 mmol) was added. The mixture was stirred at 80° C. for 3 hr. Water was added and the mixture was extracted with ethyl acetate. Organic layer was washed with water and brine, dried over magnesium sulfate and concentrated in vacuo. The residue was purified by flash chromatography on silica gel eluting with a 20-40% ethyl acetate/n-hexane gradient mixture. The filtrate was concentrated in vacuo to give the solid, which was recrystallized from ethyl acetate/n-hexane to give the title compound (45 mg, 0.109 mmol, 47%) as a colorless solid.

Provenance & Evidence