反应详情

To a solution of 740 mg (2.12 mmol) of 1-4 in 15 mL of CH2Cl2 at −78° C. was added dropwise 2.75 mL (2.75 mmol) of a 1M solution of BBr3 in CH2Cl2. After stirring for 30 min at that temperature, 1 mL of MeOH was added, and the mixture was dumped into water, extracted twice with 50 mL of CH2Cl2, washed again with water, and dried over Na2SO4. After concentration, the residue was purified by column chromatography on silica gel with a gradient of 2 to 70% EtOAc in hexanes over 30 min to provide 1-5 as a beige solid. Data for 1-5: 1HNMR (500 MHz, CDCl3) δ 7.5-7.3 (m, 5H), 7.25 (m, 1H), 7.2-7.0 (m, 3H), 6.9 (m, 1H), 5.1 (bs, 1H) ppm.

1. additionwas added
2. extractionextracted twice with 50 mL of CH2Cl2
3. washwashed again with water
4. dry with materialdried over Na2SO4
5. concentrationAfter concentration
6. customthe residue was purified by column chromatography on silica gel with a gradient of 2 to 70% EtOAc in hexanes over 30 min