Tetrahydrofuran → [9-Chloro-1-(2,4-dichloro-6-methylphenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl](dicyclopropyl)methanol
Reaction equation
[CH:1]1([Mg]Br)[CH2:3][CH2:2]1.[Cl:6][C:7]1[CH:8]=[CH:9][C:10]([C:29](OC)=[O:30])=[C:11]2[C:15]=1[N:14]=[C:13]1[N:16]([C:20]3[C:25]([CH3:26])=[CH:24][C:23]([Cl:27])=[CH:22][C:21]=3[Cl:28])[CH2:17][CH2:18][CH2:19][N:12]21.O1[CH2:37][CH2:36][CH2:35]C1>>[Cl:6][C:7]1[C:15]2[N:14]=[C:13]3[N:16]([C:20]4[C:25]([CH3:26])=[CH:24][C:23]([Cl:27])=[CH:22][C:21]=4[Cl:28])[CH2:17][CH2:18][CH2:19][N:12]3[C:11]=2[C:10]([C:29]([CH:35]2[CH2:36][CH2:37]2)([CH:1]2[CH2:3][CH2:2]2)[OH:30])=[CH:9][CH:8]=1Participants
4
Conditions
- Temperature
- 60 °C
Procedure
Cyclopropylmagnesium bromide (1.0 M solution in tetrahydrofuran, 2.4 mL, 2.4 mmol) was added to a stirred solution of methyl 9-chloro-1-(2,4-dichloro-6-methylphenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazole-6-carboxylate (200 mg, 0.471 mmol) in tetrahydrofuran (3.0 mL), and the mixture was stirred at 60° C. for 8 hr. The reaction was quenched by aqueous saturated ammonium chloride, and the mixture was 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 8-50% ethyl acetate/n-hexane gradient mixture. The filtrate was concentrated in vacuo to give the solid, which was recrystallized from ethyl acetate/diisopropyl ether to give the title compound as a colorless crystal (179 mg, 0.375 mmol, 80%).