This invention belongs to the field of
chemistry or
medicinal chemistry, specifically relating to a method for synthesizing robecoxib. The method uses 2,3,5,6-tetrafluoroaniline and
phthalic acid as raw materials, reacting them under alkaline conditions and with a catalyst to generate 5-chloro-2-(2,3,5,6-tetrafluorophenylamino)
benzoic acid. This
benzoic acid is then reacted sequentially with an
acyl chloride reagent and a diazotizing
reagent to prepare 5-chloro-1-(2,3,5,6-tetrafluorophenyl)
indoline-2-one. Following a
coupling reaction with an ethyl compound, 5-ethyl-1-(2,3,5,6-tetrafluorophenyl)
indoline-2-one is synthesized, and finally, robecoxib is obtained after
hydrolysis. In this invention, the starting materials 2,3,5,6-tetrafluoroaniline and
phthalic acid are widely available. 2,3,5,6-tetrafluoroaniline is the direct structural fragment of robecoxib, while
phthalic acid can be converted into the important functional groups of robecoxib, ethyl and
acetic acid groups, through simple functional
group transformation. This invention avoids the use of raw materials such as AlCl3, which easily generate corrosive and irritating acidic gases, thus providing a new
route for the preparation of robecoxib.