反应 #1951075

反应方程式

NH4Cl

potassium tert-butoxide

2-methylacetoacetate

6-chloro-2-methylamino-3-nitro-benzonitrile

→

2-(2-cyano-3-methylamino-4-nitro-phenyl)-2-methyl-3-oxo-butyric acid ethyl ester

收率 54.5%

溶剂

dimethylsulfoxide

Methanol

反应条件

后处理

1. 1
   其他To a 1 L two-neck round bottom flask equipped with a magnetic stir bar
2. 2
   workup.ADDITIONAfter the addition
3. 3
   其他rose to 40° C
4. 4
   萃取The mixture was extracted with EtOAc (3×150 mL)
5. 5
   洗涤washed with brine (3×100 mL)
6. 6
   干燥The organic layer was dried over sodium sulfate
7. 7
   过滤filtered
8. 8
   浓缩concentrated under vacuum
9. 9
   其他to produce a deep red oil
10. 10
    workup.STIRRINGthe mixture was stirred for 1.5 hours
11. 11
    温度with cooling over an ice bath
12. 12
    过滤The resulting precipitate was recovered by filtration
13. 13
    洗涤washed with cold methanol

实验过程

To a 1 L two-neck round bottom flask equipped with a magnetic stir bar and internal thermometer was added potassium tert-butoxide (5.0 g, 45 mmol) and dimethylsulfoxide (100 mL). To the rapidly stirred suspension was added 2-methylacetoacetate (7.13 g, 49.5 mol) dropwise over 5 minutes. After the addition was complete the mixture was clear and slightly yellow. To the reaction mixture was then added 6-chloro-2-methylamino-3-nitro-benzonitrile (8.6 g, 41 mmol) from Step 1 in portions over 15 minutes. The reaction mixture immediately became deep red in color and the temperature rose to 40° C. The reaction mixture was stirred for 1.5 hours, then poured into a saturated solution of NH4Cl (100 mL). The mixture was extracted with EtOAc (3×150 mL). The organic layers were combined and washed with brine (3×100 mL). The organic layer was dried over sodium sulfate, filtered, and concentrated under vacuum to produce a deep red oil. Methanol (40 mL) was added and the mixture was stirred for 1.5 hours with cooling over an ice bath. The resulting precipitate was recovered by filtration and washed with cold methanol to provide 2-(2-cyano-3-methylamino-4-nitro-phenyl)-2-methyl-3-oxo-butyric acid ethyl ester (7.13 g, 40.6%) as a yellow solid, which was used without further purification. 1H NMR (400 MHz, DMSO-d6) δ 8.23 (d, 1H, J=9.0 Hz), 8.10-8.05 (m, 1H), 6.64 (d, 1H, J=9.0 Hz), 4.28-4.19 (m, 2H), 3.17 (d, 3H, J=5.5 Hz), 2.36 (s, 3H), 1.81 (s, 3H), 1.22 (t, 3H, J=7.0 Hz).

来源