Reaction #2358490

Reaction equation

oxalyl chloride

5-(trifluoromethyl)benzo[b]thiophene-2-carboxylic acid

→

ethyl 5-(trifluoromethyl)benzo[b]thiophene-2-carboxylate

Yield 74.1%

Solvents

ethanol

Conditions

Workup

1. 1
   Temperaturecooling
2. 2
   Temperatureunder reflux
3. 3
   Concentrationconcentrated under reduced pressure
4. 4
   workup.ADDITIONTo the residue was added chloroform
5. 5
   Washthe organic layer was washed with saturated aqueous sodium bicarbonate solution and saturated aqueous sodium chloride solution
6. 6
   Dryingdried over magnesium sulfate
7. 7
   Concentrationconcentrated under reduced pressure

Procedure

Then, 254 mg of oxalyl chloride was added to a mixture of 400 mg of 5-(trifluoromethyl)benzo[b]thiophene-2-carboxylic acid and 20 ml of ethanol while ice-cooling, and the mixture was stirred for 6 hours under reflux. The reaction mixture was cooled to room temperature, and then concentrated under reduced pressure. To the residue was added chloroform, and then the organic layer was washed with saturated aqueous sodium bicarbonate solution and saturated aqueous sodium chloride solution, dried over magnesium sulfate, and then concentrated under reduced pressure to obtain 330 mg of ethyl 5-(trifluoromethyl)benzo[b]thiophene-2-carboxylate (the present compound 5).

Source