Reaktion #57664

Reaktionsgleichung

5-chloro-4-methoxy-3-methyl-benzofuran-2-carboxylic acid

oxalyl chloride

(S)-2-(4′-amino-biphenyl-4-sulfonylamino)-3-methyl-butyric acid methyl ester

pyridine

→

(S)-2-{4′-[(5-chloro-4-methoxy-3-methyl-benzofuran-2-carbonyl)-amino]-biphenyl-4-sulfonylamino}-3-methyl-butyric acid methyl ester

Ausbeute 87.0%

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture refluxed for 2 h
2. 2
   SonstigeThe excess oxalyl chloride was removed under vacuum
3. 3
   workup.DISSOLUTIONThe residue was dissolved in 2 mL of dichloromethane
4. 4
   workup.STIRRINGThe mixture was stirred at 0° C. overnight
5. 5
   Waschenwas washed with 2N HCl, and water
6. 6
   SonstigeRemoval of the solvent in vacuo
7. 7
   Sonstigegave the crude product which
8. 8
   Sonstigewas purified by column chromatography

Vorschrift

To 80 mg (0.33 mmol) of 5-chloro-4-methoxy-3-methyl-benzofuran-2-carboxylic acid was added 2 mL of oxalyl chloride and the mixture refluxed for 2 h, then stirred room temperature overnight. The excess oxalyl chloride was removed under vacuum. The residue was dissolved in 2 mL of dichloromethane and was added to a mixture of 181 mg (0.5 mmol) of (S)-2-(4′-amino-biphenyl-4-sulfonylamino)-3-methyl-butyric acid methyl ester and 1 mL of pyridine in an ice/water bath. The mixture was stirred at 0° C. overnight. The reaction mixture was diluted with dichloromethane and was washed with 2N HCl, and water. Removal of the solvent in vacuo gave the crude product which was purified by column chromatography to give 168 mg (86% yield) of (S)-2-{4′-[(5-chloro-4-methoxy-3-methyl-benzofuran-2-carbonyl)-amino]-biphenyl-4-sulfonylamino}-3-methyl-butyric acid methyl ester as a white solid.

Quelle