A SIMPLE AND EFFICIENT SYNTHESIS OF 1,3,6-TRISUBSTITUTED PYRAZOLOQUINOLINES VIA INTRAMOLECULAR CYCLIZATION – OPTIMIZATION STUDIES

Abstract

In this work, we developed a straightforward and convenient method for the synthesis of substituted pyrazoloquinolines – highly desirable compounds for many high-tech and biomedical applications. On the basis of intramolecular cyclization of 5-(N-aryl)aminopyrazoles in the presence of DMF diethyl acetal and POCl₃, a series of differently substituted pyrazoloquinolines were synthesized. The synthetic procedure was thoroughly optimized taking into account key factors such as the type of formylating agent (DMF vs. DMF diethyl diacetal), reaction temperature, and stoichiometry of the reagents used. Because of its versatility, simplicity, and ease in purification of the obtained products, this synthetic approach provides a valuable guideline in the rational design of pyrazoloquinoline-based functional materials.