反应详情

To a stirring solution of 4-hydroxy-benzoic acid (6.91 g, 50.03 mmol) in dry acetonitrile (250 mL) at −20° C. under an atmosphere of N2 was added HBF4-Et2O (10.50 g, 9.50 mL, 55.00 mmol) dropwise via syringe. The solution was stirred at 0° for 0.5 hours at which time solid N-iodosuccinimide (13.5 g, 60 mmol) was added at one time. The solution was left to stir for 16 hours and then filtered to remove precipitated succinimide. The solution was diluted with water (500 mL) and extracted with ethyl acetate (2×250 mL). The organic portions were combined and washed with 10% sodium bisulfite (250 mL), water (2×250 mL) and saturated aqueous NaCl (250 mL). The solvent was removed in vacuo to yield 8.76 g of crude solid. The crude solid was purified by column chromatography (6:4:0.1 hexane:ethyl acetate:formic acid) to yield 7.54 g (57%)of the desired product as white crystals. 1H NMR (DMSO-d6) δ 12.74 (br s, 1H), 11.18 (s, 1H), 8.20 (s, 8.20, 1H), 7.79 (d, 1H), 6.94 (d, 1H).

1. additionwas added at one time
2. waitThe solution was left
3. filtrationfiltered
4. customto remove
5. customprecipitated succinimide
6. additionThe solution was diluted with water (500 mL)
7. extractionextracted with ethyl acetate (2×250 mL)
8. washwashed with 10% sodium bisulfite (250 mL), water (2×250 mL) and saturated aqueous NaCl (250 mL)
9. customThe solvent was removed in vacuo
10. customto yield 8.76 g of crude solid
11. customThe crude solid was purified by column chromatography (6:4:0.1 hexane:ethyl acetate:formic acid)