The acetylation of 2-(4-aminophenyl)acetic acid (I) with acetic anhydride, followed by nitration with nitric acid in acetic acid and treatment with HCl in ethanol gives 2-(4-amino-3-nitrophenyl)acetic acid ethyl ester (II), which is reduced at the nitro group, and cyclized with SOCl2 yielding the benzothiadiazole (III). The condensation of (III) with 3-fluoro-4-methoxyphenacyl bromide (IV) by means of potassium tert-butoxide affords the 4-oxobutyrate (V), which is condensed with 3,4,5-trimethoxybenzaldehyde (VI) by means of sodium methopxide in methanol to provide the the dihydrofuranone (VII). Finally, this compound is treated with NaOH in methanol to promote the opening of the lactone ring yielding the target compound.