Hydrochloric Acid → 4,5,6,7-Tetrafluorobenzothiophen-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

78 g of 2,3,4,5,6-pentafluorobenzylidene rhodanine were added in small portions to a stirred solution of 68 g of NaOH in 300 ml of water. The resultant clear red solution was heated to 90° C. for one hour, cooled in ice, acidified with concentrated HCl, and the cream coloured solid which was produced was filtered and washed. The crude product (59 g) was purified by sublimation to give 4,5,6,7-tetrafluorobenzothiophen-2-carboxylic acid having a melting point of 200° C.

Provenance & Evidence