반응 #59249

반응 방정식

MgSO4

NaOAc

3-Methyl-2-oxo-butyric acid ethyl ester

butyl-hydrazine oxalate salt

→

crude product ( 3b )

수율 85.4%

2-(Butyl-hydrazono)-3-methyl-butyric acid ethyl ester

수율 85.4%

용매

CHCl3

반응 조건

후처리

1. 1
   온도The mixture was heated
2. 2
   온도to reflux for 3.5 hours under N2 atmosphere
3. 3
   온도After cooling
4. 4
   여과the solid was filtered off
5. 5
   농축the filtrate was concentrated under reduced vacuum
6. 6
   추출The residue was first cleaned by an extraction between EtOAc (50 mL×3) and H2O (20 mL)
7. 7
   농축The organic layer was concentrated under reduced pressure
8. 8
   기타dried under high vacuum overnight

실험 절차

To a solution of 3-Methyl-2-oxo-butyric acid ethyl ester (1c) (1.88 g, 13.04 mmol) in 45 mL of CHCl3, butyl-hydrazine oxalate salt (2.11 g, 11.85 mmol) was added followed by NaOAc (1.94 g, 23.4 mmol) and MgSO4 (1.43 g, 11.88 mmol). The mixture was heated to reflux for 3.5 hours under N2 atmosphere with stirring. After cooling, the solid was filtered off and the filtrate was concentrated under reduced vacuum. The residue was first cleaned by an extraction between EtOAc (50 mL×3) and H2O (20 mL). The organic layer was concentrated under reduced pressure and dried under high vacuum overnight to give 2.17 g of the crude product (3b) in 85.4% yield as a mixture of the E- and Z-isomers. This crude product was directly used in the next step without further purification. LC-MS (ESI+): m/e=215.4 [M+1]+, 237.1 [M+Na]+ (exact ms: 214.17).

출처