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

Participants

Reaction Steps

To a solution of 4-[4-chloro-2-[(2,6-dimethoxypyridin-3-yl)amino]-7-(1-ethylpropyl)-1H-benzimidazol-1-yl]butan-1-ol (Reference Example 44; 80 mg, 0.18 mmol) in pyridine (1.8 mL) was added methanesulfonyl chloride (0.070 mL, 0.89 mmol) dropwise at 0° C. The mixture was warmed to room temperature and stirred for 16 hr. Aqueous sodium bicarbonate was added and the mixture was extracted with ethyl acetate. Organic layer was washed with brine, dried over sodium sulfate and concentrated in vacuo. The resulting crude mesylate was dissolved in N,N-dimethylformamide (3.6 mL) and potassium carbonate (123 mg, 0.89 mmol) was added. The mixture was stirred at 80° C. for 16 hr. Water was added and the mixture was extracted with ethyl acetate. Organic layer was washed with water and brine, dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was purified by flash chromatography on silica gel eluting with a 5-20% ethyl acetate/n-hexane gradient mixture. The filtrate was concentrated in vacuo to give a solid, which was recrystallized from ethyl acetate/n-hexane to give the title compound (15 mg, 0.035 mmol, 19%) as a colorless solid.

Provenance & Evidence