反应详情

To a solution of Intermediate 296A (1.2 g, 4.99 mmol) in ethanol (5 mL) was added a 5N aq. solution of NaOH (4.99 mL, 24.97 mmol) and the reaction mixture was stirred at RT for 4 h. The reaction mixture was concentrated under reduced pressure; the residue was dissolved in water and extracted with diethyl ether (3×5 mL) The pH of the aqueous solution was adjusted to 7.0 using a 2N aq. solution of HCl and extracted with DCM (3×10 mL). The combined organic layers were dried over Na2SO4, filtered and concentrated to afford Intermediate 296B as a pale yellow liquid (500 mg, 67%). 1H NMR (400 MHz, DMSO-d6) δ ppm 12.73-12.70 (m, 1H), 3.03-2.89 (m, 2H), 2.49-2.41 (m, 2H), 1.40 (s, 3H).

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. dissolutionthe residue was dissolved in water
3. extractionextracted with diethyl ether (3×5 mL) The pH of the aqueous solution
4. extractionextracted with DCM (3×10 mL)
5. dry with materialThe combined organic layers were dried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated