Reaction #170974

Reaction equation

6-[4-(2-hydroxyethoxycarbonylamino)phenoxy]hexanoic acid methyl ester

6-[4-(2-Hydroxyethoxycarbonylamino)-phenoxy]-hexanoic acid methyl ester

6-(4-isocyanatophenoxy)-hexanoic acid methyl ester

6-(4-Isocyanatophenoxy)-hexanoic acid methyl ester

→

20

Yield 95.0%

6-(4-{2-[4-(5-Methoxycarbonyl-pentyloxy)-phenylcarbamoyloxy]-ethoxycarbonylamino}-phenoxy)-hexanoic acid methyl ester

Yield 95.0%

Solvents

toluene

Conditions

Workup

1. 1
   workup.DISTILLATIONToluene was distilled
2. 2
   workup.ADDITIONwater (50 ml) was added
3. 3
   FiltrationThe solid was filtered
4. 4
   Otherdried
5. 5
   Otherto give crude 20, which
6. 6
   Otherwas purified by column chromatography on silica gel

Procedure

To a mixture of 6-[4-(2-hydroxyethoxycarbonylamino)phenoxy]hexanoic acid methyl ester 19 (5 g, 15.38 mmol) in toluene (50 ml) was added 6-(4-isocyanatophenoxy)-hexanoic acid methyl ester 18 (4 g, 15.2 mmol) at room temperature and heated to 60° C. for 2 hours. Toluene was distilled and water (50 ml) was added. The solid was filtered and dried to give crude 20, which was purified by column chromatography on silica gel using chloroform as eluant to get pure 20 (8.5 g, 94%) as a white powder with an m.p. between 118-120.5° C.

Source