反応 #9011

反応方程式

AlCl3

CH3SCN

BCl3

m-cresol

→

2-Hydroxy-4-methylbenzonitrile

収率 91.1%

溶媒

1,2-dichloroethane

反応条件

後処理

1. 1
   その他2-Hydroxy-4-methylbenzonitrile was prepared
2. 2
   その他The cooling bath was removed
3. 3
   温度then cooled to room temperature
4. 4
   workup.ADDITIONThe mixture was poured into 4 N NaOH (35 mL)
5. 5
   温度the mixture was heated at 80° C. for 45 minutes
6. 6
   温度then cooled to room temperature
7. 7
   その他The phases were separated
8. 8
   抽出the aqueous phase was extracted with CH2Cl2 (3×50 mL)
9. 9
   抽出extracted with diethyl ether (3×50 mL)
10. 10
    乾燥The combined ether extracts were dried (MgSO4)
11. 11
    濃縮concentrated
12. 12
    その他Purification of the crude material by column chromatography on silica gel (20:1 CH2Cl2—EtOAc)

実験手順

2-Hydroxy-4-methylbenzonitrile was prepared following a modification of the procedure reported by Makoto Adachi and Tsutomu Sugasawa (Synthetic Communications 1990, 20, 71–84.). To a cold (0° C.) solution of BCl3 (1.0 M in heptane, 12.0 mL, 12.0 mmol) in 1,2-dichloroethane was added neat m-cresol (1.00 mL, 9.56 mmol) followed by CH3SCN (0.83 mL, 12.1 mmol) and AlCl3 (1.38 g, 10.4 mmol). The cooling bath was removed and the resultant mixture was heated to 80° C. for 3 hours then cooled to room temperature. The mixture was poured into 4 N NaOH (35 mL) and the mixture was heated at 80° C. for 45 minutes then cooled to room temperature. The phases were separated and the aqueous phase was extracted with CH2Cl2 (3×50 mL). The aqueous phase was acidified with 6 N HCl (30 mL) and extracted with diethyl ether (3×50 mL). The combined ether extracts were dried (MgSO4) and concentrated. Purification of the crude material by column chromatography on silica gel (20:1 CH2Cl2—EtOAc) provided 1.16 g (91%) of 2-Hydroxy-4-methylbenzonitrile as a white solid. 1H NMR (CDCl3) δ 2.36 (s, 3H), 6.20 (br s, 1H), 6.79–6.81 (m, 2H), 7.38 (d, 1H, J=9 Hz).

出典