Abstract

This paper discloses the syntheses and structural studies of a two series of compounds derived from 3-Methoxysalicylaldehyde ( o-vanillin), which were synthesized in three-step procedure, which includes the protection of o-vanillin forming compound 1 and. then, the nitration of these compounds generates the formation of the regioisomers 2a and 2b, which were successfully separated. These compounds were treated with a strong base, obtaining the precursors 3a and 3b, respectively. In the case of compound 3c, this was synthesized by direct nitration of o-vanillin. Finally, compounds 3a-3c were methylated, ob-taining compounds 4a-4c. The synthesized compounds were characterized by spectroscopic techniques, where the structures of 3a-3c, and 4b-4c were confirmed by X-ray diffraction techniques. The inter-molecular contacts were studied by Hirshfeld surface analyses. Crystal topology was analyzed by energy framework studies in order to observe further physical chemical properties, such as the development of potential high-dose prolonged-release drugs for long-term control of Parkinson's disease in advanced patients, related to entacapone derivates.(c) 2022 Elsevier B.V. All rights reserved.