2,4,5-Triphenylimidazole → 7-(1,2,4-Triphenyl-imidazolyl)-hept-5-ynoic acid

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Reaction Steps

A solution of 2,4,5-triphenylimidazole (1.07 g) in dimethyl-formamide (20 ml) was treated with sodium hydride 50% in oil (0.17 g) and methyl 7-bromohept-5-ynoate (0.95 g). The solution was stirred for 18 hours when the solvent was removed under reduced pressure and the residue was chromatographed on silica gel eluted with chloroform-hexane to give a clear oil which was dissolved in methanol (20 ml) and treated with 10% potassium hydroxide solution (10 ml) for 2 hours. The methanol was removed under reduced pressure and the remaining aqueous was acidified (pH 3) and filtered. The filtrate was extracted with chloroform (3×50 ml). The chloroform extracts were dried over magnesium sulphate, filtered and the solvent removed to give a solid which was recrystallised from acetonitrile to give 7-(1,2,4-triphenyl-imidazolyl)-hept-5-ynoic acid as white prisms, m.p. 144°-145° C.; Found: C, 79.99; H, 5.81; N, 6.40% (C28H24N2O2);Requires: C, 79.97; H, 5.75; N, 6.66%

Provenance & Evidence