合成路线1

The reaction of 3-fluoroaniline (I) with isobutyl chloroformate (II) by means of K2CO3 in dichloromethane/water gives the carbamate (III), which is brominated with 1,3-dibromo-5,5-dimethylhydantoin (DBDH) to yield the 4-bromo-3-fluorophenyl carbamate (IV). The condensation of (IV) with tetrahydrothiopyran-4-one (V) by means of EtMgBr and BuLi in THF affords the tertiary alcohol (VI), which is dehydrated by means of TFA in dichloromethane and oxidized with NaIO4 in methanol/water to provide the unsaturated sulfoxide (VII). The stereoselective reduction of (VII) by means of H2 over Pt/C in DMF gives the cis sulfoxide (VIII). The cyclization of the carbamate (VIII) with (S)-3-chloropropane-1,2-diol (IX) by means of Li t-amylate in DMF gives the oxazolidinone (X), whose free OH group is activated with 2,5-dichlorobenzenesulfonyl chloride (XI) and TEA in dichloromethane to yield the sulfonate (XII). The reaction of (XII) with NH4OH in methanol/acetonitrile affords the aminomethyl derivative (XIII), which is finally acylated with acetic anhydride (XIV) to provide the target sulfoxide.