Reactivity of 4,5-Dichlorophthalic Anhydride towards Thiosemicarbazide and Amines: Synthesis, Spectroscopic Analysis, and DFT Study

The cyclic anhydrides are broadly employed in several fields, such as the chemical, plastic, agrochemical, and pharmaceutical industries. This study describes the chemical reactivity of 4,5-dichlorophthalic anhydride towards several nucleophiles, including thiosemicarbazide and different amines, to produce the carboxylic acid derivatives resulting from anhydride's opening, namely, phthalimide and dicarboxylic acid (1-12) products. Their chemical structures are confirmed by NMR, IR and MS spectra analyses. Density-functional theory (DFT) studies are performed using (DFT/B3LYP) with the 6-311G(d, p) basis sets to recognize different chemical and physical features of the target compounds.