合成路线1

Friedel-Crafts acylation of acetanilide (I) with 2-chloropropionyl chloride (II) in the presence of AlCl3 provided ketone (III). The chlorine atom of (III) was then displaced with dimethylamine to afford amino ketone (IV), which was reduced to alcohol (V) using NaBH4 in MeOH. Treatment of alcohol (V) with carbonyl diimidazole furnished the imidazolyl derivative (VI). The acetamido group of (VI) was then hydrolyzed with 3N HCl to give aniline (VII). This compound was converted to isothiocyanate (VIII) by treatment with thiophosgene and NaOH. Alternatively, aniline (VII) was treated with carbon disulfide and NaOH and then with iodomethane to give the bis(methylthio)methyleneamino derivative (IX). The condensation of either (VIII) or (IX) with 2-aminothiophenol (X) produced the target benzothiazole (XI) as a mixture of isomers. Then, separation of the diastereoisomers by column chromatography, followed by resolution by chiral HPLC, furnished the title (S,S)-isomer.