Spectral investigations of some piperidin-4-one molecular addition compounds

Abstract In the present study, some 2- and 3-substituted piperidin-4-ones (A1-A3) were chosen as proton acceptor and maleic anhydride was chosen as proton donor. Piperidin-4-ones (A1, A2 ---amp--- A3) were mixed with maleic anhydride in ether medium and the corresponding molecular adduct products (B1, B2 ---amp--- B3) thus obtained were collected and purified. The 1H and 13C NMR spectra were recorded for piperidine-4-one and their addition compounds. The 1H and 13C NMR chemical shifts of products (B1, B2 ---amp--- B3) are analyzed and compared with those of the corresponding piperidine-4-ones (A1, A2 ---amp--- A3). In order to confirm the formation of molecular addition compounds the GC-Mass spectrum was recorded for all adducts B1-B3 and the fragmentations patterns were analyzed.