反応 #502081

反応方程式

N,N′-dicyclohexylcarbodiimide

7-acetoxycoumarin-4-acetic acid

2,2,2-trichloroethanol

→

product 6a

収率 96.7%

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

収率 96.7%

溶媒

dichloromethane

dichloromethane

dichloromethane

反応条件

後処理

1. 1
   ろ過filtered
2. 2
   濃縮The filtrate was concentrated under vacuum

実験手順

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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