反应详情

To a suspension of 4-(methylsulfonyl)aniline hydrochloride (10.5 g, 0.051 mmol) in toluene (500 mL) was added trimethylaluminum (2M solution in toluene, 75.0 mL, 0.150 mmol) over 15 minutes at 0° C. The reaction mixture was warmed up to room temperature and stirred for 2 hours. A solution of 3-cyano-5-methylpyridine from step 3 in 90 mL of toluene was added over 10 minutes and the mixture was stirred at 85°-90° C. for 16 hours. The reaction mixture was cooled to room temperature and filtered through a slurry of silica gel. After filtration, the residue was washed with methanol (800 mL). The combined filtrate was concentrated under reduced pressure and the residue was treated with a mixture of ether and hexane (2/1, 1000 mL). The brownish solid was filtered and washed with more ether and hexane to give 11.8 g of N-[4-(methylsulfonyl)phenyl]-5methylnicotinamidine (80%). To a mixture of the above crude amidine (11.3 g, 0.039 mmol) and sodium bicarbonate (9.83 g, 0.12 mmol) in isopropanol (400 mL) was added 3-bromo-1,1,1-trifluoroacetone (11.2 g, 0.059 mmol) quickly at room temperature. After heating the reaction mixture at 75°-80° C. for 16 hours, the solvent was removed and the residue was partitioned between water and methylene chloride. The organic layers were washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The crude was purified by chromatography on silica gel (ethyl acetate/acetone, 98:2) to give pure 3-methyl-5-[4-hydroxy-1-[4-(methylsulfonyl)phenyl]-4-(trifluoromethyl)-4,5-dihydro-1H-imidazol-2-yl]pyridine as a yellow solid (3.85 g, 25%): mp (DSC) 237°-239° C; Anal. Calc'd. for C17H16F3N3O3S: C, 51.12, H, 4.04, N, 10.52, S, 8.03. Found: C, 51.02, H, 3.94, N, 10.19, S, 8.11.

1. stirringthe mixture was stirred at 85°-90° C. for 16 hours
2. temperatureThe reaction mixture was cooled to room temperature
3. filtrationfiltered through a slurry of silica gel
4. filtrationAfter filtration
5. washthe residue was washed with methanol (800 mL)
6. concentrationThe combined filtrate was concentrated under reduced pressure
7. additionthe residue was treated with a mixture of ether and hexane (2/1, 1000 mL)
8. filtrationThe brownish solid was filtered
9. washwashed with more ether and hexane