Methyl iodide → 5-(3,5-dichlorophenylthio)-1-methyl-4-isopropyl-2-(p-methoxybenzyloxymethyl)-1H-imidazole

Beteiligte Stoffe

Reaktionsschritte

(5)In 25 ml of dry N,N-dimethylformamide was dissolved 11.0 g (25.1 mmol)of 5-(3,5-dichlorophenylthio)-4-isopropyl-2-(p-methoxybenzyloxymethyl)-1H-imidazole (16b), followed by addition of 5.2 g (38 mmol)of potassium carbonate powder. Then, 3.90 g (27.7 mmol)of methyl iodide was further added and the mixture was stirred at room temperature for 8 hours. This reaction mixture was concentrated under reduced pressure and the residue was diluted with water and extracted with diethyl ether. The organic layer was washed with water and dried over magnesium sulfate. The solvent was distilled off under reduced pressure and the residue was fractionated by silica gel chromatography (ethyl acetate:methylene chloride=1:9). From the first fraction, 1.7 g (yield 15%)of the objective position isomer (17b')was obtained as oil. From the subsequent fraction, 9.14 g (yield 80%)of the objective 5-(3,5-dichlorophenylthio)-1-methyl-4-isopropyl-2-(p-methoxybenzyloxymethyl)-1H-imidazole (17b)was obtained. mp 79-80° C.

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