反应详情

A solution of methyl 2,4,5,7-tetrafluorofluorene-9-carboxylate (1.49 g, 5.03 mmol) in dry THF (15 mL) was added over 14 min to a stirred, room temperature suspension of unwashed sodium hydride (1.25 eq, 6.29 mmol, 250 mg of a 60% oil dispersion) in THF (15 mL). The mixture was then cooled in an ice water bath and after 9 min a solution of N-chlorosuccinimide (1.2 eq, 6.04 mmol, 810 mg) was added over 14 min. After slowly warming to room temperature, the mixture was stirred for 21 h before it was poured into 100 mL of water and extracted with ethyl acetate. The extracts were washed with aqueous sodium carbonate, aqueous sodium bisulfate, and brine, dried (MgSO4), and concentrated to leave 1.4 g of crude material. Chromatography on silica gel using 20% ethyl acetate in hexane provided 970 mg (58%) of nearly pure material: 1H NMR (CDCl3) δ7.20 (dd, 2H), 7.0-6.6 (m, 2H), 3.75 (s, 3H); IR (KBr) 1730, 1600, 1580, 1410, 1105 cm-1 ; MS m/z 330 (M+), 271 (base peak).

1. additionwas added over 14 min
2. extractionextracted with ethyl acetate
3. washThe extracts were washed with aqueous sodium carbonate, aqueous sodium bisulfate, and brine
4. dry with materialdried (MgSO4)
5. concentrationconcentrated
6. customto leave 1.4 g of crude material