Clean Preparation of Quinolin-2-yl Substituted Ureas in Water

Abstract

An environmentally-friendly method for the clean preparation of various quinolin-2-yl substituted ureas in water under mild and toxic reagent-, base-, and organic solvent-free conditions was established. In the large-scale synthesis, the products could be rapidly collected via simple filtration and washing with ethanol. The usage of readily available raw materials, 100% atom economy, high yield, and excellent regioselectivity enhanced the practicability of this protocol.

Recent Advances in the Synthesis of C2‐Functionalized Pyridines and Quinolines Using N‐Oxide Chemistry

“…In 2019, He's team disclosed the Cu‐catalyzed synthesis of quinolin‐2‐yl substituted ureas in water (Scheme 29). [51] which was initiated by a [3+2] cycloaddition between quinoline N ‐oxides and carbodiimides. The reaction is exceptionally green because it involves 100% atom economy, water as solvent, and easy operation.…”

An efficient 3-acylquinoline synthesis from acetophenones and anthranilviaC(sp3)–H bond activation mediated by Selectfluor

“…1). [12][13][14] The synthesis of quinolines has been an active area for many years and as a result, a number of efficient synthetic methods have been developed, [15][16][17][18][19][20] such as the classical Skraup, [21][22][23] Combes, [24][25][26] Friedlander, [27][28][29] Gould-Jacobs, [30][31][32] and Doebner-von Miller reactions. [33][34][35][36] More recently, alternative strategies for the quinoline synthesis such as domino cycloadditions [37][38][39][40][41] and transition-metal mediated methods [42][43][44][45] have been introduced.…”

Green Decarboxylative Aminoalkylation of Coumarin‐3‐Carboxylic Acids

“…To achieve this goal, chemists have made a huge effort to proceed reactions in benign solvents and under catalyst‐free condition . Conducting a reaction in water as the inexpensive and green solvent led to the reduced levels of hazardous chemical wastes, generated from the chemical process . Apart from, the disposing of deactivated catalysts is still of notable matter from environmental point of view.…”