Réaction #170978

Équation de réaction

1,3-di-cyclohexyl carbodiimide

(4-nitrophenoxy)acetic acid

(4-Nitrophenoxy)acetic acid

(4-nitrophen-oxy)-acetic acid-2-hydroxyethyl ester

(4-Nitrophenoxy)-acetic acid-2-hydroxy-ethyl ester

→

24

Rendement 54.0%

(4-Nitrophenoxy)-acetic acid-2-[2-(4-nitrophenoxy)-acetoxy]-ethyl ester

Rendement 54.0%

Solvants

dichloromethane

dichloro-methane

Conditions de réaction

Traitement

1. 1
   FiltrationThe solids were filtered off
2. 2
   workup.DISTILLATIONdichloromethane distilled off
3. 3
   Autreto get crude 24
4. 4
   AutreThe crude 24 was purified by column chromatography on silica gel

Mode opératoire

To a mixture of (4-nitrophenoxy)acetic acid 22 (80 g, 406 mmol) and (4-nitrophen-oxy)-acetic acid-2-hydroxyethyl ester 23 (80 g, 332 mmol) in anhydrous dichloro-methane (2 L) under nitrogen atmosphere was added a solution of 1,3-di-cyclohexyl carbodiimide (128 g, 620 mmol) in anhydrous dichloromethane (750 ml) drop wise. The reaction mixture was stirred at room temperature for 8 hours. The solids were filtered off and dichloromethane distilled off to get crude 24. The crude 24 was purified by column chromatography on silica gel using hexane:ethyl acetate (95:5) to get pure 24 (75 grams, 54%) as a white powder with an m.p. between 138-139° C.

Source