반응 #59256

반응 방정식

HCl

[(2-Ethoxycarbonyl-acetyl)-(3-methyl-butyl)-hydrazono]-thiophen-2-yl-acetic acid ethyl ester

sodium ethoxide

→

desired product ( 13a )

수율 83.2%

5-Hydroxy-2-(3-methyl-butyl)-3-oxo-6-thiophen-2-yl-2,3-dihydro-pyridazine-4-carboxylic acid ethyl ester

수율 83.2%

용매

EtOH

반응 조건

후처리

1. 1
   추출followed by liquid-liquid extraction with H2O/EtOAc
2. 2
   세척The combined organic layer was washed with brine
3. 3
   건조dried over MgSO4
4. 4
   농축concentrated under reduced pressure
5. 5
   기타the residue was purified by flash chromatography on silica gel

실험 절차

To a solution of [(2-Ethoxycarbonyl-acetyl)-(3-methyl-butyl)-hydrazono]-thiophen-2-yl-acetic acid ethyl ester (12a) (380 mg, 1.0 mmol) in EtOH (6 mL) at room temperature, sodium ethoxide (Aldrich) (21 wt % in ethanol, 0.4 mL, 1.1 mmol) was added, and the resulting mixture was stirred for 30 min. Aqueous HCl (5%, 0.75 mL) was added slowly, and then followed by liquid-liquid extraction with H2O/EtOAc. The combined organic layer was washed with brine, dried over MgSO4, concentrated under reduced pressure and the residue was purified by flash chromatography on silica gel to give the desired product (13a) (280 mg, 83%) as yellow solid. LC-MS (ESI+): m/e=337.30 [M+1]+(exact ms: 336.11); 1H NMR (400 MHz, CDCl3): δ 7.89 (dd, 1H, J=3.6, 1.2 Hz), 7.39 (dd, 1H, J=5.2, 1.2 Hz), 7.10 (dd, 1H, J=5.2, 3.6 Hz), 4.53 (q, 2H, J=7.2 Hz), 4.22 (m, 2H), 1.73 (m, 2H), 1.68 (m, 1H), 1.50 (t, 3H, J=7.2 Hz), 0.99 (d, 6H, J=6.4 Hz).

출처