The reaction of isatoic anhydride (I) with glycine ethyl ester (II) gives N-(2-aminobenzoyl)glycine ethyl ester (III), which is cyclized with carbonyldiimidazole (CDI) to yield 2-(2,4-dioxo-1,2,3,4-tetrahydroquinazolin-3-yl)acetic acid ethyl ester (IV). The alkylation of (IV) with 3,4-dichlorobenzyl bromide (V) affords 2-[1-(3,4-dichlorobenzyl)-2,4-dioxo-1,2,3,4-tetrahydroquinazolin-3-yl]acetic acid ethyl ester (VI), which is finally hydrolyzed in basic medium.