Hydrochloric Acid → 1-(2,4-Dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazole-6-carboxylic acid

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Reaction Conditions

Reaction Steps

A mixture of methyl 1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazole-6-carboxylate (Example 81; 10.0 g, 26.6 mmol), methanol (100 mL), 8.0 M aqueous sodium hydroxide (150 mL) was stirred at 90° C. for 2 hr. The mixture was acidified with 6.0 M hydrochloric acid, and the precipitate was collected by filtration, washed with water, washed with ethyl acetate to give the title compound as a colorless powder (8.47 g, 23.4 mmol, 88%).

Provenance & Evidence