反応 #7001

反応方程式

NaNO2

5-methoxy-2-methyl aniline

HCl

HBF4

→

3-fluoro-4-methyl anisole

収率 31.0%

溶媒

H2O

反応条件

後処理

1. 1
   workup.ADDITION40 mmol) was added cautiously
2. 2
   ろ過the resultant brown solid was filtered
3. 3
   洗浄washed with ice water (3×10 mL) and H2O (2×10 mL)
4. 4
   その他The solid was dried under high vacuum for 20 h
5. 5
   温度heated
6. 6
   温度(heat gun) until evolution of BF3 (white fumes)
7. 7
   その他The resulting brown oil was partitioned between EtOAc and H2O
8. 8
   乾燥The organic phase was dried (Na2SO4)
9. 9
   濃縮concentrated in vacuo
10. 10
    workup.DISTILLATIONdistilled by Kugelrohr

実験手順

A mixture of 5-methoxy-2-methyl aniline (5.0 g; 36 mmol), HCl (7.6 mL of a 12 M solution; 91 mmol) and H2O (11 mL) was heated at 60° C. for 15 min until complete dissolution had occurred. The reaction was cooled to 0° C. and an aqueous solution of NaNO2 (2.5 g; 36 mmol) was added dropwise (internal temperature ≦7° C.). The reaction was stirred at 0° C. for 30 min and a 0° C. solution of HBF4 (5.3 mL of a 48% solution; 40 mmol) was added cautiously. The reaction was stirred at 0° C. for 20 min, and the resultant brown solid was filtered, washed with ice water (3×10 mL) and H2O (2×10 mL). The solid was dried under high vacuum for 20 h, then heated (heat gun) until evolution of BF3 (white fumes) had ceased. The resulting brown oil was partitioned between EtOAc and H2O. The organic phase was dried (Na2SO4), concentrated in vacuo and distilled by Kugelrohr to give 3-fluoro-4-methyl anisole (1.6 g; 31%) as a colorless oil.

出典