Diethyl Ether → 4-Acetyl-2-butyl-5-cyano-1-tritylimidazole

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Reaction Steps

11.1 ml of a 2M solution of methylmagnesium iodide in diethyl ether was slowly added dropwise at room temperature, in an atmosphere of nitrogen, to a solution of 4.5 g of 2-butyl-1-tritylimidazole-4,5-dicarbonitrile [prepared as described in step (i) above] in 45 ml of tetrahydrofuran, and the resulting mixture was stirred at room temperature for 3 hours. At the end of this time, a saturated aqueous solution of ammonium chloride was added dropwise, whilst ice-cooling, to the mixture. The tetrahydrofuran layer was separated, washed with a saturated aqueous solution of sodium chloride and concentrated by evaporation under reduced pressure to give a concentrate. The aqueous layer was once again extracted with a small amount of ethyl acetate. The extract was washed with a saturated aqueous solution of sodium chloride, dried and concentrated by evaporation under reduced pressure. The resulting extract was combined with the above concentrate, and the resulting crude product was purified by column chromatography through silica gel, using a 3:1 by volume mixture of hexane and ethyl acetate as the eluent, and the product was crystallized from a mixture of ethyl acetate and hexane, to give 1.46 g of the title compound, melting at 159°-160° C. (with decomposition).

Provenance & Evidence