تفاعل #502081

معادلة التفاعل

N,N′-dicyclohexylcarbodiimide

7-acetoxycoumarin-4-acetic acid

2,2,2-trichloroethanol

→

product 6a

المردود 96.7%

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

المردود 96.7%

المذيبات

dichloromethane

dichloromethane

dichloromethane

ظروف التفاعل

المعالجة

1. 1
   ترشيحfiltered
2. 2
   تركيزThe filtrate was concentrated under vacuum

الإجراء التجريبي

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]+.

المصدر