Benzamidine → 1-(2-Phenyl-1H-imidazol-5-yl)ethan-1-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 1 (2.2 g, 13.3 mmol) in 20 ml 1,4-dioxane was added benzamidine (3.24 g, 20.0 mmol) and sodium acetate (2.83 g, 33.3 mmol). The reaction was refluxed in an oil bath at 110° C. over 60 hours. After the reaction was cooled to room temperature, the salt was removed through a plug of celite and the filtrate was concentrated to a red oil. This oil was then taken up in ethyl acetate (50 ml) and extracted with 1N HCl (17 ml×3). The combined aqueous layers were basified with aqueous Na2CO3 and then were extracted with ethyl acetate (50 ml×3). The combined organic layers were dried over Na2SO4 and the solvent was removed. Purification by chromatography using CH2Cl2/MeOH (95:5/v:v) afforded 2′ (1.02 g) as the desired product in 41% yield. 1H NMR (acetone-d6, ppm) δ: 7.4-8.1 (m, 7H) and 2.42 (s, 3H).

Provenance & Evidence