반응 #1005975

반응 방정식

6-methoxy-2,2-dimethyl-thiochroman-4-one

BBr3

→

6-hydroxy-2,2-dimethylthiochroman-4-one

수율 40.0%

용매

CH2Cl2

CH2Cl2

반응 조건

후처리

1. 1
   온도was cooled to −78° C.
2. 2
   기타quenched by the slow addition of 50 mL of H2O
3. 3
   온도Upon warming to room temperature the aqueous layer
4. 4
   추출was extracted with CH2Cl2
5. 5
   세척the combined organic layers were washed with saturated aqueous NaHCO3, H2O, and saturated aqueous NaCl
6. 6
   건조before being dried over MgSO4
7. 7
   기타Removal of the solvents under reduced pressure
8. 8
   기타gave a green-brown solid which
9. 9
   기타upon recrystallization (Et2O/hexanes)

실험 절차

To a solution of 6-methoxy-2,2-dimethyl-thiochroman-4-one (6.0 g, 27 mmol) in 50 mL CH2Cl2 cooled to −23° C. was added BBr3 (20.0 g, 80.0 mmol; 80.0 mL of a 1M solution in CH2Cl2) over a 20 minute period. After stirring for 5 hours at −23° C. the solution was cooled to −78° C. and quenched by the slow addition of 50 mL of H2O. Upon warming to room temperature the aqueous layer was extracted with CH2Cl2 and the combined organic layers were washed with saturated aqueous NaHCO3, H2O, and saturated aqueous NaCl before being dried over MgSO4. Removal of the solvents under reduced pressure gave a green-brown solid which upon recrystallization (Et2O/hexanes) afforded 2.25 g (40%) of 6-hydroxy-2,2-dimethylthiochroman-4-one as a light brown solid. 1H NMR (300 MHz, CDCl3) δ: 7.63 (1H, d, J=2.8 Hz), 7.15 (1H, d, J=8.5 Hz), 7.01 (1H, dd, J=2.8, 8.5 Hz), 2.87 (2H, s), 1.46 (6H, s).

출처