反应详情

温度

60 °C

A solution of methyl 2′,4′-dimethoxy-2-methylbiphenyl-4-carboxylate obtained in step 2 (2 g; 6.99 mmol) in EtOH (60 mL) at RT was treated with sodium hydroxide (4.19 mL; 5 M; 20.96 mmol). The reaction mixture was stirred at 60° C. for 1 hour. The reaction mixture was concentrated to give a brown solid that was taken up in water (40 mL) and the aqueous phase was washed twice with EtOAc and then acidified with HCl to pH 2. Then it was concentrated until precipitation (⅕ of the volume). The suspension was filtered off and dried under vacuum affording the title compound as an orange solid. 1H NMR (DMSO-d6, 300 MHz) δ 12.59 (br s, 1H), 7.58-7.51 (m, 2H), 6.97-6.95 (d, J=8.03 Hz, 1H), 6.81-6.79 (d, J=8.39 Hz, 1H), 6.44-6.37 (m, 2H), 3.59 (s, 3H), 3.49 (s, 3H), 1.88 (s, 3H). LC/MS (Method A): 272.9 (M+H)+; 270.9 (M−H)−. HPLC (Method A) Rt 3.87 min (Purity: 99.7%).

1. concentrationThe reaction mixture was concentrated
2. customto give a brown solid that
3. washthe aqueous phase was washed twice with EtOAc
4. concentrationThen it was concentrated until precipitation (⅕ of the volume)
5. filtrationThe suspension was filtered off
6. customdried under vacuum