Ethyl 5-bromovalerate → 5-(4,5-diphenyl-1H-imidazol-2-ylthio)pentanoic acid ethyl ester

Beteiligte Stoffe

Reaktionsschritte

Part A. To a solution of 4,5-diphenyl-2-imidazolethiol (25.2 g, 0.1 mol) in N,N-dimethylformamide (250 mL) was added, dropwise, a solution of ethyl 5-bromopentanoate (23.73 mL, 31.35 g, 0.15 mol) in N,N-dimethylformamide (80 mL), and the reaction mixture was stirred at reflux under nitrogen for 18 hours. The reaction mixture was cooled, poured into 5% sodium bicarbonate and ice, and then extracted with ethyl acetate. The combined organic extracts were washed sequentially with 5% sodium bicarbonate, water, saturated sodium chloride solution, dried over magnesium sulfate, and concentrated under vacuum. The residue was chromatographed with 7:3 hexane-ethyl acetate, and the resulting solid was recrystallized from acetonitrile and triturated with hexane to give 5-(4,5-diphenyl-1H-imidazol-2-ylthio)pentanoic acid ethyl ester (25.95 g, 0.068 mol) as a white solid, mp 87°-89°. 1H NMR (DMSO-d6) δ 7.55-7.15 (m,11H), 4.0(q,2H,J=8 Hz) , 2.9(t,2H,J= 7 Hz) , 2.3(t,2H,J=7 Hz), 1.9-1.6(m,4H), 1.2(t,3H,J=8 Hz).

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