Reaction #725895

Reaction equation

6-(4-Amino-phenoxy)-hexanoic acid hydrochloride

6-(4-Amino-phenoxy)-hexanoic acid Hydrochloride

methanol

HCl

→

21

6-(4-Amino-phenoxy)-hexanoic acid methyl ester

Conditions

Workup

1. 1
   Otherat 10° C.
2. 2
   Otherfor 1 hour
3. 3
   Temperaturerefluxed for 48 hours
4. 4
   workup.DISTILLATIONMethanol (1.5 liter) was distilled off
5. 5
   workup.ADDITIONice water (1 liter) was added
6. 6
   ExtractionCrude 21 was extracted into chloroform
7. 7
   Washwashed with 5% NaHCO3 solution in water
8. 8
   Dryingdried over Na2SO4
9. 9
   workup.DISTILLATIONdistilled

Procedure

To a mixture of 6-(4-Amino-phenoxy)-hexanoic acid hydrochloride 20 (150 grams, 578 mmol) in methanol (3 liters) was passed dry HCl gas at 10° C. for 1 hour and refluxed for 48 hours. Methanol (1.5 liter) was distilled off, ice water (1 liter) was added and the pH was adjusted to 7.5 with K2CO3. Crude 21 was extracted into chloroform, washed with 5% NaHCO3 solution in water, dried over Na2SO4 and distilled to give 21 (60 g, 43.8) as a thick brown syrup. The structure was confirmed with NMR.

Source