反应详情

A solution of 9 (314 mg, 1.30 mmol) in MeOH (10.8 mL) at room temperature was treated dropwise with 3 M HCl (3.46 mL, 10.3 mmol), then heated to reflux for 1 hour. Water (11 mL) was added and the solution was extracted with EtOAc (3×15 mL). Combined organic fractions were washed with saturated aqueous NaCl, dried (Na2SO4), filtered, and concentrated to afford 10 as a red amorphous solid (177 mg, 99%): 1H NMR (CDCl3, 500 MHz) 8.17 (s, 1H), 6.09 (d, J=1.6 Hz, 1H), 6.04 (s, 1H), 3.67 (d, J=9.9 Hz, 3H), 2.08 (d, J=4.1 Hz, 3H); 13C NMR (CDCl3, 125 MHz) 60.3, 157.8, 155.4, 108.4, 93.9, 93.8, 55.0, 7.0; IR (film) νmax 3445, 2924, 2853, 2359, 2332, 1653, 1636, 1456, 1080, 1022, 798, 669 cm−1; HRMS (ESI+) m/z: [2M+H]+ calcd for C8H10O3, 309.1338 found, 309.1332.

1. temperatureheated
2. temperatureto reflux for 1 hour
3. extractionthe solution was extracted with EtOAc (3×15 mL)
4. washCombined organic fractions were washed with saturated aqueous NaCl
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated