반응 #649603

반응 방정식

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

수율 54.5%

용매

dimethylsulfoxide

Methanol

반응 조건

후처리

1. 1
   기타To a 1 L two-neck round bottom flask equipped with a magnetic stir bar
2. 2
   workup.ADDITIONAfter the addition
3. 3
   기타rose to 40° C
4. 4
   추출The mixture was extracted with EtOAc (3×150 mL)
5. 5
   세척washed with brine (3×100 mL)
6. 6
   건조The organic layer was dried over sodium sulfate
7. 7
   여과filtered
8. 8
   농축concentrated under vacuum
9. 9
   기타to produce a deep red oil
10. 10
    workup.STIRRINGthe mixture was stirred for 1.5 hours
11. 11
    온도with cooling over an ice bath
12. 12
    여과The resulting precipitate was recovered by filtration
13. 13
    세척washed with cold methanol

실험 절차

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 mmol) 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).

출처