2-Phenyl-3,4-dihydro-2H-1-benzothiopyran-4-one (I) was converted to oxime (II) upon treatment with hydroxylamine, and subsequently reduced to amine (III) by means of Zn and HOAc. Condensation of (III) with thiocarbonyl diimidazole (IV) produced the thioimidazolide (V), that was displaced with 2-bromoethyl amine (VI) to furnish thiourea (VII). Finally, cyclization of the N-(bromoethyl)thiourea (VII) in the presence of Et3N produced the target thiazoline derivative.