Tetrahydrofuran → 2-Aminomethyl-5-(3,5-dichlorophenylthio)-4-isopropyl-1-methylimidazole

Participants

Reaction Steps

To dry tetrahydrofuran solution (60 ml) of 24.2 g of 2-azidomethyl-5-(3,5-dichlorophenylthio)-4-isopropyl-1-methyl-1H-imidazole (29a) was added 19.6 g of tripenylphosphine under ice-cooling, and the mixture was stirred at room temperature for 4 hours. After the reaction completion was confirmed (the disappearance of 29a) by TLC (silica gel, methylene chloride-ethyl acetate=10:1), 50 ml of water was added, and the mixture was stirred at room temperature for 1.5 hours, and left overnight. Tetrahydrofuran was distilled off under reduced pressure, and to the residue, 400 ml of 3N-hydrochloric acid was added. When the mixture was washed with diethyl ether, crystals were precipitated from the hydrochloric acid layer. The crystals were collected by filtration, and neutralized with a saturated aqueous sodium hydrogen carbonate solution. The mixture was extracted with diethyl ether. The aqueous layer was also neutralized with a saturated aqueous sodium hydrogen carbonate solution, and was extracted with diethyl ether. These ether extracts were combined and dried over magnesium sulfate. The solvent was distilled off under reduced pressure, and 20.6 g of 2-aminomethyl-5-(3,5-dichlorophenylthio)-4-isopropyl-1-methyl-1H-imidazole (30a) was obtained (yield 92%). mp 86-87° C.

Provenance & Evidence