Potassium Carbonate → Methyl 9-chloro-1-(2-methoxy-4,6-dimethylpyrimidin-5-yl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazole-6-carboxylate

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Reaction Conditions

Reaction Steps

Methanesulfonyl chloride (4.57 mL, 57.8 mmol) was added to a stirred solution of methyl 4-chloro-1-(3-hydroxypropyl)-2-[(2-methoxy-4,6-dimethylpyrimidin-5-yl)amino]-1H-benzimidazole-7-carboxylate (Reference example 127, 11.9 g, 28.9 mmol) and triethylamine (12.1 mL) in tetrahydrofuran (400 mL) at 0° C. The mixture was stirred at 0° C. for 50 min, and concentrated in vacuo. A mixture of the resulting mesylate and potassium carbonate (12.0 g, 86.8 mmol) in N,N-dimethylformamide (200 mL) was stirred at 80° C. for 2 hr. The mixture was diluted with aqueous saturated ammonium chloride, 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 purified by flash column chromatography on silica gel eluting with a 50-100% ethyl acetate/n-hexane gradient mixture. The filtrate was concentrated in vacuo to give the title compound as a pale yellow solid (8.88 g, 22.1 mmol, 76% in 2 steps).

Provenance & Evidence