1,2,3,6-Tetrahydrophthalic anhydride (1) was used as a precursor for the synthesis of new cyclic imides by reacting with several reagents such as 2-aminothiazole, 4-aminopyridine, 2-aminobenzothiazole, cyanoacetic acid hydrazide, amino guanidine, 2,2-diaminomalononitrile, hexamethylenediamine or 2-(amino-ethyldisulfanyl)-ethylamine where the corresponding cyclic imides 2-9 were obtained respectively. Similarly, a series of tetrahydroquinazolin-2,4-diones 11-20 have been synthesized from the reaction of 2-phenylsulphonyloxy-3a,4,7,7a-tetrahydroisoindol-1,3-dione 10 with different amino compounds as hetero-amines, amino acids, and diamines. The proposed structures of the synthesized compounds were supported by their elemental and spectral analyses as well as their semiempirical MOPAC calculations. Semiempirical MOPAC calculations have been also performed to uncover the fundamental reaction pathway of the anhydride 1 with 4-aminopyridine as a model reaction and compound 10 with different amino compounds. The in vitro study of some selected imides and quinazolin-2,4-dinoes against two strains of bacteria possesses a high inhibition effect.