Triethylamine → 1H-Imidazole-2-ethanol, 5-((3,5-dichlorophenyl)thio)-4-(1-methylethyl)-1-((4-nitrophenyl)methyl)-, carbamate (ester)

Participants

Reaction Conditions

Reaction Steps

In 5 ml of tetrahydrofuran was dissolved 467 mg (1 mmol) of 5-(3,5-dichlorophenylthio)-2-(2-hydroxyethyl)-4-isopropyl-1-p-nitrobenzyl-1H-imidazole (126a), and there was added 0.23 g (1.2 mmol) of trichloroacetylisocyanate under stirring on a cooling bath at -20° C. Then, the bath was taken off, and the mixture was reacted for 2 hours. To the reaction mixture was added a saturated aqueous sodium hydrogen carbonate solution, and extracted with methylene chloride. The extract was washed with water, dried, and the solvent was distilled off, and the trichloroacetylcarbamoyloxy compound which was able to use for the next reaction, was obtained in the residue. The intermediate was dissolved in 10 ml of aqueous methanol (10%), followed by addition of 0.2 ml of triethylamine under stirring at room temperature, and the mixture was stirred with heating at 50° C. for 3 hours and worked up. When the crystals were precipitated, the mixture was filtered directly. When the crystals were not precipitated, a saturated aqueous sodium hydrogen carbonate solution was added to the reaction mixture, and extracted with methylene chloride. The extract was washed with water and dried, the solvent was distilled off, and the residue was purified by silica gel column chromatography (ethyl acetate) to give 2-(2-carbamoyloxyethyl)-5-(3,5-dichlorophenylthio)-4-isopropyl-1-(p-nitrobenzyl)-1H-imidazole (128a) as oil (yield 98%).

Provenance & Evidence