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.

合成路线2

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 dehydroxylated by means of poly(methylhydrosiloxane) (PMHS), (Me3Si)2O and Ts-OH in toluene to provide the intermediate (VII). The stereoselective oxidation of (VII) to the trans sulfoxide (VIII) is performed by means of Ti(OiPr)4 and tert-butyl hydroperoxide in the presence of diisopropyl D-tartrate. 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 3-nitrobenzenesulfonyl chloride 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 propionic anhydride (XIV) to provide the target sulfoxide.

合成路线3

合成路线4

合成路线5

合成路线6

Condensation of 1,2-difluoro-4-nitrobenzene (I) with thiomorpholine (II) using DIEA in refluxing acetonitrile at 85 °C yields 4-(2-fluoro-4-nitrophenyl)thiomorpholine (III) , which is then reduced by means of either Na2S2O4 in THF , Fe in the presence of NH4Cl in refluxing H2O/EtOH/dioxane , or by catalytic hydrogenation over Raney-Ni in THF/H2O (1) or sulfided Pd/C in MeOH , providing 3-fluoro-4-thiomorpholin-4-ylaniline (IV) . Acylation of amine (IV) with benzyl chloroformate (V), optionally in the presence of DMA , in THF affords carbamate (VI) , which then cyclizes with (R)-(–)-glycidyl butyrate (VII) using BuLi in THF at –78 °C to produce the 5-(hydroxymethyl)-2-oxazolidinone derivative (VIII). Reaction of the primary alcohol (VIII) with MsCl using Et3N in CH2Cl2 or with TsCl in pyridine yields the corresponding mesylate (IXa) or tosylate (IXb) , respectively, which by substitution with NaN3 in DMF at 65-85 °C provides azide (X). Staudinger reduction of azide (X) with PPh3 in THF/H2O then yields the corresponding amine (XIa). Finally, amine (XIa) or its hydrochloride (XIb) are acylated with acetic anhydride (XII) in the presence of pyridine in CH2Cl2 or NaOH in H2O/MeOH/CH2Cl2 .