Reaktion #57773

Reaktionsgleichung

HCl

Benzofuran-2-carboxylic acid

oxalyl chloride

4′-amino-biphenyl-4-sulfonic acid

N,N-diisopropylethylamine

→

4′-[(benzofuran-2-carbonyl)-amino]-biphenyl-4-sulfonic acid

Ausbeute 85.8%

Lösungsmittel

DMF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe excess oxalyl chloride was removed by vacuum
2. 2
   workup.DISSOLUTIONThe residue was dissolved in 4 ml of dichloromethane
3. 3
   Sonstigeformed
4. 4
   SonstigeThe solid was collected by centrifugation
5. 5
   Waschenwas washed with chloroform and 2N HCl

Vorschrift

Benzofuran-2-carboxylic acid (310 mg, 1.9 mmol) was mixed with 3 ml of oxalyl chloride and refluxed for 1 h in the presence of a catalytic amount of DMF, then the excess oxalyl chloride was removed by vacuum. The residue was dissolved in 4 ml of dichloromethane and was added to a mixture of 400 mg (1.6 mmol) of 4′-amino-biphenyl-4-sulfonic acid, N,N-diisopropylethylamine (0.92 ml, 4 eq) and 4 ml of THF in an ice/water bath. The mixture was stirred at room temperature for 4 h. The reaction mixture was mixed with 2N HCl and in the process a suspension formed. The solid was collected by centrifugation and was washed with chloroform and 2N HCl to provide 540 mg of 4′-[(benzofuran-2-carbonyl)-amino]-biphenyl-4-sulfonic acid, obtained as pale brown solid.

Quelle