Study of Thermal and Photochemical Reactions of 2-Methoxy-1,4-napthoquinone With Amines.

Abstract

Aminoquinones are a group of compounds that have potential anti-cancer properties. 2-Methoxy-1,4-napthoquinone was used as a starting molecule in the synthesis of aminoquinones. We have found the reactive site of 2-methoxy-1,4-napthoquinone is dependent upon the reaction conditions. The thermal reaction leads to substitution at the 2-position, replacing the methoxy group with the amine in good yield. Methanol was the most effective solvent for the thermal reaction. Slower reaction rates were observed for amines with secondary alkyl groups than for those with primary alkyl groups. Interestingly, the photochemical substitution did not occur at the 2-position, but rather at the 3-posititon. The most successful solvent was benzene when kept cold to suppress any of the thermal reaction. The reactivity difference between the 2 and 3-positions can be explained by the electron density calculation of the contributing orbitals