合成路线1

Oxidation of 2-fluoro-4-nitrotoluene (I) by means of Jones reagent afforded the benzoic acid (II). After activation of (II) as the corresponding acid chloride with SOCl2, reaction with lithium tert-butoxide furnished the tert-butyl ester (III). Reduction of the nitro group of (III) by means of iron powder gave amine (IV), which was further converted into the carbamate (V) upon treatment with benzyl chloroformate. The chiral oxazolidinone (VII) was prepared by condensation of the lithium salt of carbamate (V) with (R)-glycidyl butyrate (VI) at -78 C. After activation of the primary hydroxyl of (VII) as the corresponding mesylate, displacement with NaN3 in hot DMF provided the alkyl azide (VIII). Tert-Butyl ester cleavage in (VIII) employing trifluoroacetic acid afforded the carboxylic acid (IX), which was cyclized to the thiadiazole (XI) by condensation with thiosemicarbazide (X) in the presence of POCl3. Reduction of the azido group of (XI) to the primary amine (XII) was accomplished by treatment with triphenylphosphine followed by aqueous hydrolysis. Finally, acylation of the aliphatic amino group of (XII) with ethyl dithioacetate gave rise to the title thioacetamide.