Acetaldehyde → 9-Chloro-1-(2,4-dichlorophenyl)-N,N-diethyl-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-amine

Participants

Reaction Steps

To a solution of 9-chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-amine (45 mg, 0.122 mmol) in methanol (5.0 mL) and acetic acid (1.0 mL) was added acetaldehyde (0.10 mL, 1.64 mmol) at 0° C. The resultant mixture was stirred at 0° C. for 30 min. To the reaction mixture was added sodium triacetoxyborohydride (346 mg, 1.64 mmol) at 0° C. After stirring at room temperature for 1 hr, the mixture was concentrated in vacuo, diluted with water, and extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by column chromatography on a silica gel eluting with a 10-50% ethyl acetate/n-hexane gradient mixture. The filtrate was concentrated in vacuo to give the title compound (50 mg, 0.120 mmol, 98%) as a white amorphous.

Provenance & Evidence