Sodium Chloride → {Phenethyl-(5-(3-propyl)-1H-imidazole-2-carbonyl)amino}acetic acid tert-butyl ester

Participants

Reaction Steps

A 0° C. solution of 4-(3-phenylpropyl)-imidazole-2-carboxylic (13d) (150 mg, 0.65 mmol) and N-(2-phenylethyl)glycine tert-butyl ester (140 mg, 0.59 mmol) in 5 ml of anhydrous dimethylformamide was treated with diisopropylethylamine (154 μl, 0.89 mmol), hydroxy-benzotriazole (160 mg, 1.18 mmol), and 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride (136 mg, 0.71 mmol). After stirring for 36 h, the reaction was poured onto saturated aqueous sodium chloride and extracted with ethyl acetate (3×50 ml) The combined organic extracts were washed twice with saturated aqueous sodium bicarbonate (2×) and saturated aqueous sodium chloride (1×), dried (Na2SO4), filtered, and concentrated in vacuo to give a brown oil. Chromatography (flash, SiO2, 30% ethyl acetate/hexane) to give 160 mg (61%) of 23 as a white solid: 1H NMR (CDCl3) δ 7.38-7.14 (10H, m), 6.85-6.8 (1H, m), 4.84-4.76 (1H, d), 4.5-4.42 (1H, m), 4.07-4.0 (1H, d), 3.78-3.72 (1H, m), 3.12-2.94 (2H, 2×m), 2.75-2.55 (4H, m), 2.1-1.95 (2H,m), 1.5-1.45 (9H, 3×s).

Provenance & Evidence