4-Bromobenzoic hydrazide has been used in the preparation of {2-[1-oxo-3-(4-bromophenyl)-2-propenyl]hydrazide}-4-bromobenzoic acid, {2,2?-[1,4-phenylenebis(1-oxo-2-propene-3,1-diyl)]dihydrazide}-p-bromobenzoic acid and substituted period[1,2-a]pyrimidine-2,4(3H)-diones (PPMDO).