Triphenylphosphine → 1-[9-Chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl]-2,2,2-trifluoroethanamine

Participants

Reaction Steps

A solution of 6-(1-Azido-2,2,2-trifluoroethyl)-9-chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazole (68.2 mg, 0.143 mmol) and triphenylphosphine (56.3 mg, 0.215 mmol) in tetrahydrofuran (5.0 mL) and water (0.10 mL) was stirred at 60° C. for 20 hr. The reaction mixture was concentrated in vacuo and the residue was purified by flash column chromatography on silica gel eluting with a 30-100% ethyl acetate/n-hexane gradient mixture to give 1-[9-Chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl]-2,2,2-trifluoroethanamine as a white solid (67.2 mg). To a solution of 1-[9-Chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl]-2,2,2-trifluoroethanamine (67.9 mg) and pyridine (0.12 mL, 1.48 mmol) in tetrahydrofuran (5.0 mL) was added acetyl chloride (0.051 mL, 0.717 mmol) at 0° C. The mixture was stirred at 0° C. for 1 hr. Aqueous sodium hydrogen carbonate was added to the reaction mixture at room temperature and the mixture was extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous magnesium sulfate, and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel eluting with a 25-80% ethyl acetate/n-hexane gradient mixture to give the title compound (33.1 mg, 0.067 mmol, 47%) as white crystals.

Provenance & Evidence