Hydrochloric Acid → 2-Benzenesulphonylamino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid

Participants

Reaction Steps

A solution of potassium trimethylsilanoate (0.141 g) in dry THF (5 ml) was added to a cooled solution of ethyl 2-benzenesulphonylamino-4,5,6,7-tetrahydro-benzo[b]thiophene-3-carboxylate (Intermediate 1, 0.076 g) in dry THF (5 ml). The resultant cloudy solution was stirred at room temperature for 2 hours. Further potassium trimethylsilanoate (0.076 g) was added and the resultant mixture was stirred for a total of 72 hours. The mixture was then stirred and heated at 60° C. for a total of 48 hours. The resultant mixture was diluted with water and acidified to pH1 by addition of concentrated hydrochloric acid and extracted with ethyl acetate. The organic phase was washed with water, dried (MgSO4) and filtered. The filtrate was evaporated to dryness and the residue was triturated with ether. The solid was collected by filtration and air dried to give 2-benzenesulphonylamino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid (0.034 g) as an off white solid.

Provenance & Evidence