The acylation of 2,3-dihydrobenzofuran (I) with acetyl chloride and AlCl3 in dichloromethane gives 5-acetyl-2,3-dihydrobenzofuran (II), which by reaction with sulfur, morpholine (III) and p-toluenesulfonic acid at high temperature yields 2-(2,3-dihydrobenzofuran-5-yl)thioacetic acid morpholide (IV). The hydrolysis of (IV) with H2SO4 in refluxing water-acetic acid affords 2-(2,3-dihydrobenzofuran-5-yl) acetic acid (V), which is esterified to (VI) with ethanol and H2SO4 in refluxing toluene. The condensation of the ester (VI) with 4-(methylthio)benzoyl chloride (VII) by means of SnCl4 in refluxing dichloromethane gives ethyl 2-[7-[4-(methylthio)benzoyl]benzofuran-5-yl]acetate (VIII), which by hydrolysis with NaOH in refluxing methanol-water yields the corresponding acid (IX). Finally, this compound is dehydrogenated with N-bromosuccinimide (NBS) and dibenzoyl peroxide in refluxing CCl4.