4-bromo-N-tert-butylbenzamide → 4-[3-(4-Tert-butylaminocarbonylphenyl)-3-hydroxyprop-1-yl]-1-tritylimidazole

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Reaction Steps

A solution of 25 mmoles of n-butyllithium in 10 ml of hexane is added dropwise to a solution of 3.19 g of N-tert-butyl 4-bromobenzamide in 250 ml of tetrahydrofuran at -70° under argon. After 30 min, a solution of 3.74 g of 3-(1-tritylimidazol-4-yl)propionaldehyde in 100 ml of tetrahydrofuran is added slowly. The reaction mixture is stirred at -70° for 30 min, allowed to warm to 25°, stirred at 25° for 2.5 h and quenched with excess saturated ammonium chloride solution. The aqueous layer is separated and extracted with methylene chloride (2×100 ml). The combined organic extracts are dried over sodium sulfate and evaporated. The residue is chromatographed on 220 g of silica with 5:1 ether:ethyl acetate to yield 4-[3-(4-tert-butylaminocarbonylphenyl)-3-hydroxyprop-1-yl]-1-tritylimidazole as an oil. IR (CH2Cl2): 1660 cm-1.

Provenance & Evidence