반응 #81854

반응 방정식

2-hydroxybenzenecarbothioamide

2-Hydroxybenzenecarbothioamide

ethyl 4-chloroacetoacetate

NaHCO3

CO2

NaHCO3

→

4a

수율 93.0%

2-(2-Hydroxyphenyl)-4-thiazoleacetic Acid Ethyl Ester

수율 93.0%

용매

EtOAc

THF

반응 조건

후처리

1. 1
   온도to reflux under nitrogen for 2.5 days
2. 2
   기타The organic layer was separated
3. 3
   세척washed with brine (40 mL×2)
4. 4
   건조dried over MgSO4
5. 5
   여과filtered
6. 6
   농축After concentration in vacuo
7. 7
   기타the oily residue was chromatographed on silica gel gradient EtOAc/CH2Cl2

실험 절차

A stirred solution of 2-hydroxybenzenecarbothioamide 3a (5.36 g, 35.0 mmol), ethyl 4-chloroacetoacetate (6.34 g, 38.5 mmol) in dry THF (70 mL) was heated to reflux under nitrogen for 2.5 days. At ambient temperature, the mixture was diluted with EtOAc (200 mL), then cautiously treated with saturated aq. NaHCO3 (40 mL), and followed by adding solid NaHCO3 in small portions until CO2 evolution ceased. The organic layer was separated, washed with brine (40 mL×2), dried over MgSO4, and filtered. After concentration in vacuo, the oily residue was chromatographed on silica gel gradient EtOAc/CH2Cl2 :0-4%) to provide 4a (8.53 g, 93%) as a white solid, which was recrystallized from toluene/hexane at -30° C. mp 35.5-36.5° C.; IR (neat) 3120, 1740, 480, 1225 cm-1 ; 1H NMR (DMSO-d6) δ1.15 (3H, t, J=7.1 Hz, CH3), 3.84 (2H, t, CH2), 4.07 (2H, q, J=7.1 Hz, CH2), 6.89 (1H, S, J=7.8 Hz, Ar), 6.97 (1H, d, J=7.8 Hz, Ar), 7.26 (1H, t, J=7.8 Hz, Ar), 7.48 (1H, s, 7.93 (1H, d, J=7.8 Hz, Ar, 11.29 (1H, s, OH); FABMS m/z 263 (M30 ), 264 (M+ +1); Anal. Calcd for C13H13NO3S: C, 59.30; H, 4.98; N, 5.32. Found: C, 59.16; H, 4.97; N, 5.50.

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