반응 #1994297

반응 방정식

(E)-4-(4-chloro-2-fluorophenyl)-but-3-en-2-one

diethyl oxalate

Sodium

ethyl alcohol

sodium

→

(E)-6-(4-chloro-2-fluoro-phenyl)-2,4-dioxo-hex-5-enoic acid ethyl ester

수율 86.5%

(E)-6-(4-chloro-2-fluorophenyl)-2,4-dioxo-hex-5-enoic acid ethyl ester

수율 86.5%

용매

ether

반응 조건

후처리

1. 1
   기타the solvent was removed under reduced pressure, and anhydrous ether (200 mL)
2. 2
   workup.ADDITIONwas added
3. 3
   여과the yellow solid was filtered
4. 4
   세척washed with ether
5. 5
   기타After 1 hour (h) of drying at room temperature
6. 6
   기타the solid was partitioned between CH2Cl2 (200 mL) and 1 N sulfuric acid (H2SO4, 150 mL)
7. 7
   건조The organic layer was dried (MgSO4)
8. 8
   기타the solvent was removed

실험 절차

Sodium pellets (2.88 g, 0.125 mol) were slowly added to absolute ethyl alcohol (EtOH, 125 mL). After the sodium had reacted, the solvent was removed under reduced pressure, and anhydrous ether (200 mL) was added. The reaction mixture was cooled to −5° C., and a solution of (E)-4-(4-chloro-2-fluorophenyl)-but-3-en-2-one (1; 24.75 g, 0.125 mol) and diethyl oxalate (21.9 g, 0.15 mol) in anhydrous ether (25 mL) was added over 30 min. After stirring 2 days (d) at room temperature, the yellow solid was filtered and washed with ether. After 1 hour (h) of drying at room temperature, the solid was partitioned between CH2Cl2 (200 mL) and 1 N sulfuric acid (H2SO4, 150 mL). The organic layer was dried (MgSO4), and the solvent was removed to give (E)-6-(4-chloro-2-fluoro-phenyl)-2,4-dioxo-hex-5-enoic acid ethyl ester (3; 32.3 g, 86%) as a yellow solid. A small sample was recrystallized from EtOH to yield yellow crystals: mp 84-85° C.; 1H NMR (400 MHz, CDCl3) δ 14.72 (s, 1H), 7.76 (d, J=16.1 Hz, 1H), 7.49 (d, J=8.3 Hz, 1H), 7.24-7.12 (m, 2H), 6.73 (d, J=16.1 Hz, 1H), 6.53 (s, 1H), 4.38 (q, J=7.1 Hz, 2H), 1.40 (t, J=7.1 Hz, 3H); HRMS-ESI (m/z): calcd for C14H12ClFO44, 298.041. found, 298.041.

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