反应 #1597031

反应方程式

HCl

n-BuLi

DMF

2-chloro-6-fluoro-3-methoxy-quinoxaline

→

aldehyde

收率 76.0%

2-chloro-6fluoro-3-methoxy-quinoxaline-5-carbaldehyde

收率 76.0%

溶剂

EA

THF

THF

EA

AcOH

反应条件

后处理

1. 1
   温度After cooling to −78° C.
2. 2
   workup.STIRRINGThe reddish mixture was stirred at −78° C. for 40 min
3. 3
   其他the internal temperature below −70° C
4. 4
   workup.WAITThe reaction proceeded 20 min
5. 5
   温度Once the mixture had warmed up to rt
6. 6
   其他were obtained
7. 7
   其他The two layers were separated
8. 8
   萃取the aq. layer was extracted with EA (3×300 mL)
9. 9
   洗涤layer was washed twice with sat. aq. NaHCO3 (200 mL) and brine (200 mL)
10. 10
    干燥dried over MgSO4
11. 11
    过滤filtered
12. 12
    浓缩concentrated to dryness
13. 13
    其他The crude product was triturated with an ether-EA mixture (1-1, 250 mL)
14. 14
    洗涤washed with ether (2×100 mL)
15. 15
    其他dried under high vacuum

实验过程

To a solution of DIPA (22.3 mL) in THF (150 mL) was added at −20° C., n-BuLi (2.3M, 63.7 mL, 159 mmol). The mixture was stirred at −20° C. for 10 min. After cooling to −78° C., a solution of 2-chloro-6-fluoro-3-methoxy-quinoxaline (27.1 g, 127.4 mmol) in THF (100 mL+10 mL rinse) was added over 40 min. The reddish mixture was stirred at −78° C. for 40 min. DMF (15 mL) was added keeping the internal temperature below −70° C. The reaction proceeded 20 min. AcOH (15 mL) was added. Once the mixture had warmed up to rt, 3M HCl (180 mL) and EA (500 mL) were added. The mixture was further diluted with EA (400 mL) until two clear layers were obtained. The two layers were separated and the aq. layer was extracted with EA (3×300 mL). The org. layer was washed twice with sat. aq. NaHCO3 (200 mL) and brine (200 mL), dried over MgSO4, filtered and concentrated to dryness. The crude product was triturated with an ether-EA mixture (1-1, 250 mL), washed with ether (2×100 mL), and dried under high vacuum to afford the title aldehyde as a beige solid (23 g, 76% yield).

来源