Sodium sulfate decahydrate → 9-Chloro-1-(2,4,6-trichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazole-6-carbaldehyde

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Reaction Steps

To a suspension of lithium aluminum hydride (53.7 mg, 1.42 mmol) in tetrahydrofuran (5 mL) was added a solution of methyl 9-chloro-1-(2,4,6-trichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazole-6-carboxylate (210 mg, 0.472 mmol) in tetrahydrofuran (5 mL) at 0° C., and the resultant mixture was stirred at 0° C. for 5 min. After sodium sulfate decahydrate (500 mg) was added at 0° C., the resultant mixture was filtered and concentrated in vacuo to give a crude solid. To a solution of the crude solid in acetonitrile (5 mL) and dimethylsulfoxide (1 mL) was added Dess-Martin reagent (240 mg, 0.566 mmol) at room temperature, and the resultant mixture was stirred at room temperature for 30 min, diluted with aqueous sodium bicarbonate and ethyl acetate, filtered and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel eluting with a 10-50% ethyl acetate/n-hexane gradient mixture to give the title compound as a colorless solid (166 mg, 0.400 mmol, 85%).

Provenance & Evidence