反应详情

A round-bottom flask was charged with dimethyl 2′-cyano-4′-methylbiphenyl-3,5-dicarboxylate (1.5 g, 4.4 mmol), ethanol (100 mL), 1,4-dioxane (20 mL), and a solution of sodium hydroxide (0.17 g, 4.4 mmol) in water (10 mL). The mixture was stirred at room temperature for 3 h. The volatiles were removed under reduced pressure, and the residue was acidified with 1N aq. HCl to pH=4 and extracted with CH2Cl2. The combined organic layers were dried and concentrated. The residue was purified via flash chromatography to afford the desired product 2′-cyano-5-(methoxycarbonyl)-4′-methylbiphenyl-3-carboxylic acid as a white solid. 1H NMR (400 MHz, DMSO-d6): 13.58 (br, 1H), 8.56 (t, J=1.3 Hz, 1H), 8.34-8.31 (m, 2H), 7.85 (s, 1H), 7.65 (d, J=2.6 Hz, 2H), 3.92 (s, 3H), 2.42 (s, 3H). 3-Ethyl 5-methyl 2′-cyano-4′-methylbiphenyl-3,5-dicarboxylate was also isolated as a white solid.

1. customThe volatiles were removed under reduced pressure
2. extractionextracted with CH2Cl2
3. customThe combined organic layers were dried
4. concentrationconcentrated
5. customThe residue was purified via flash chromatography