反应详情

A mixture of Example 470A (9.8 g, 50.7 mmol), DMF (50 mL), and dichloromethane (150 mL) was cooled to 0° C., treated portionwise with N-bromosuccinimide (12.6 g, 76 mmol), stirred until all the starting material was consumed, and filtered. The filter cake was washed with dichloromethane combined filtrates were concentrated, treated with anhydrous methanol (450 mL), and heated to reflux for 54 hours. Purification by flash column chromatography on silica gel with 15% ethyl acetate/hexanes provided the desired product. MS (ESI(+)) m/e 260, 262 (M+H)+, 277, 279 (M+NH4)+, 282, 284 (M+Na)+; (ESI(−)) m/e 258, 260 (M−H)−; 1H NMR (300 MHz, DMSO-d6) δ 7.34 (d, 1H), 6.50 (d, 1H), 5.63 (s, 2H), 3.82 (s, 3H), 3.71 (s, 3H).

1. customwas consumed
2. filtrationfiltered
3. washThe filter cake was washed with dichloromethane combined filtrates
4. concentrationwere concentrated
5. additiontreated with anhydrous methanol (450 mL)
6. temperatureheated
7. temperatureto reflux for 54 hours
8. customPurification by flash column chromatography on silica gel with 15% ethyl acetate/hexanes