The problem of searching biologically active compounds amidst xanthine derivatives is a crucial one and is an issue for long-term investigation. Aim. In order to find new biologically active compounds among xanthine derivatives, undescribed earlier 8-benzylidenhydrazino-1-p-methylbenzyltheobromines have been synthesized. Methods and results. Reaction of 1-p-methylbenzyl-8-bromoxanthine with the excess of hydrazine hydrate in the aqueous dioxane is implemented through formation of 8-hydrazine-1(4-methylbenzyl)theobromine. Through the interaction of 8-hydrazinetheobromine with aldehydes in aqueous propan-2-ol respective 8-benzylidenhydrazino-1-p-methylbenzyltheobromines have been obtained. Structure of synthesized compounds has been definitely proved by NMR-spectroscopy. Conclusions. Molecular and pharmacological descriptors of obtained substances have been calculated. The antioxidant activity of the obtained compounds has been explored. Priorities for further search of biologically active compounds in a range of xanthine derivatives have been set out.