LAUSR

Synthesis of (E)-2-hydroxy-5-(aryldiazenyl)benzaldehydes was investigated. Various Lewis acids were tested as catalyst to achieve regioselectivity. In addition to various commercial catalysts, mesoporous Zn/SBA-15 was synthesized through a modified direct method with chloride salt as zinc precursor and characterized using N2-physisorption, low-angle XRD, FESEM and EDX methods; specific surface area of 832 m2 g−1 is a noteworthy result compared to the literature. The synthesized catalyst showed the best results in terms of both total yield and regioselectivity. A scalable two-phase reaction media was used to facilitate both reaction progress monitoring and final product separation. Minimizing solvent consumption, this method can be considered for larger scale production of aryl azo dyes and related compounds.