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

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.