Thiophenol (I) is treated with mesityl oxide (II) in CHCl3 and Et3N to yield derivative (III), which is then converted into alcohol (IV) by means of methylmagnesium iodide in Et2O. Cyclization of (IV) by means of AlCl3 in CS2 affords benzothiopyrane derivative (V) (1), which is nitrated by means of HNO3 and Ac2O or HOAc followed by treatment with Na2CO3 to provide (VI). Nitro derivative (VI) is then reduced with TiCl3 and HOAc or HCl and treated with NaOH to yield (VII). Amine (VII) is finally acylated with acid chloride (VIII) in benzene and pyridine.