Synthesis and theoretical study on 5,6-Dimethoxy-2,3-dihydro- 7H-dibenzo[de,h]quinolin-7-one: Possible precursor on the aromatic demethoxylation in oxoisoaporphines

5,6-Dimethoxy-2,3-dihydro-7H-dibenzo[de,h] quinolin-7-one has been synthesized by cyclization of phenylethylaminophtalides with polyphosphoric acid and characterized by X-ray diffraction and NMR assignments. A theoretical study by using DFT hybrid method B3LYP and the 6-311++G(2d,p) basis set has been carried out. The local reactivity descriptors such as Fukui functions, local softness and local electrophilicity were calculated on the isolated molecule. The results of the calculations were compared with experimental data for understanding the aromatic demethoxylation to afford 5-methoxy-2,3-dihydro-7H- dibenzo[de,h]quinolin-7-one as final product.