반응 #502081

반응 방정식

N,N′-dicyclohexylcarbodiimide

7-acetoxycoumarin-4-acetic acid

2,2,2-trichloroethanol

→

product 6a

수율 96.7%

(2′,2′,2′-Trichloroethyl) 7-acetoxycoumarin-4-acetate

수율 96.7%

용매

dichloromethane

dichloromethane

dichloromethane

반응 조건

후처리

1. 1
   여과filtered
2. 2
   농축The filtrate was concentrated under vacuum

실험 절차

To a suspension of 7-acetoxycoumarin-4-acetic acid 5 (945 mg, 3.6 mmol, 1 eq) in 47 mL of anhydrous dichloromethane at room temperature under nitrogen was added 2,2,2-trichloroethanol (431 μL, 4.5 mmol, 1.25 eq). A solution of N,N′-dicyclohexylcarbodiimide (818 mg, 4 mmol, 1.1 eq) in 10 mL of anhydrous dichloromethane was added. The reaction mixture was stirred for 15 min, after which it was diluted with dichloromethane and filtered. The filtrate was concentrated under vacuum. Column chromatography on silica gel (CH2Cl2 then CH2Cl2:EtOAc, 10:1) afforded product 6a (1.37 g, 96%): Rf 0.78 (CH2Cl2:EtOAc, 5:1); 1H NMR (300 MHz, CDCl3): δ 7.61 (d, 1H, J5,6 8.7 Hz, H-5), 7.15 (d, 1H, J6,8 2.1 Hz, H-8), 7.07 (dd, 1H, J6,8 2.3, J5,6 8.7 Hz, H-6), 6.42 (s, 1H, H-3), 4.77 (s, 2H, CH2CCl3), 3.91 (2 s, 2H, CH2CO2), 2.33 (s, 3H, OAc); 13C NMR (75 MHz, CDCl3): δ 168.6, 167.0, 154.5, 153.5, 146.5, 125.5, 118.5, 117.0, 116.5, 110.9, 74.6, 37.7, 21.2; ESI-MS: m/z 393 [M+H]+.

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