合成路线1

The reaction of 4-(methylsulfanyl)acetophenone (I) with tosylhydrazine by means of PPTS in acetonitrile gives the corresponding hydrazone (II), which by reaction with isopropylmagnesium chloride in THF/toluene yields the vinylmagnesium derivative (III). This compound, without isolation is condensed with 3,5-difluorobenzaldehyde (IV) to afford the allyl alcohol (V), which is condensed with triethyl orthoacetate and saponified providing 5-(3,5-difluorophenyl)-4-[4-(methylsulfanyl)phenyl]-4-pentenoic acid (VI). The cyclization of (VI) with AlCl3 and (COCl)2 in dichloromethane gives the cyclopentenone (VII), which is finally oxidized with potassium peroxymonosulfate (Oxone) in hot acetone/water to afford the target sulfone.