Potassium Carbonate → Methyl 9-chloro-1-[6-(dimethylamino)-4-methylpyridin-3-yl]-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazole-6-carboxylate

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Reaction Steps

Methanesulfonyl chloride (1.7 mL, 21.0 mmol) was added to a stirred solution of methyl 4-chloro-2-{[6-(dimethylamino)-4-methylpyridin-3-yl]amino}-1-(3-hydroxypropyl)-1H-benzimidazole-7-carboxylate (Reference example 119, 2.20 g, 5.26 mmol) and triethylamine (3.7 mL) in tetrahydrofuran (26 mL) at 0° C. The mixture was stirred at room temperature for 13 hr, and concentrated in vacuo. A mixture of the resulting mesylate, potassium carbonate (2.18 g, 15.8 mmol) in N,N-dimethylformamide (30 mL) was stirred at 80° C. for 4 hr. The mixture was diluted with aqueous sodium hydrogen carbonate, and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The residue was washed with diisopropyl ether to give the title compound as a colorless powder (1.22 g, 3.05 mmol, 58% in 2 steps).

Provenance & Evidence