Environmental Friendly Synthesis of Bis-Perfluoropyridine and Pyrimidine in Water

Abstract

Listen

Translate article

An easy, efficient and simple approach for the synthesis of some perfluoropyridine and pyrimidine derivatives by reaction of pentafluoropyridine and tetrafluoropyrimidine with mono and bidentate N-nucleophiles in the presence of potassium carbonate in water as a green solvent, at room temperature is reported. The structures of some products were unambiguously confirmed by X-ray crystallography. INTRODUCTION Organic reactions in aqueous media have attracted considerable attention in recent years, since they offer a powerful tool for minimizing waste production and harmful organic solvent dispersal.1 Some particular properties of water make this solvent very attractive (e.g., non-toxicity, non-inflammability, high heat capacity, possibility of controlling pH, isolating insoluble solid products by filtration and recycling inorganic catalysts and itself), allowing organic processes in aqueous medium to be safer, very efficient, and highly selective.2 Because water is natural, abundant, cheap, and readily available, it is thought to be an ideal solvent for both laboratory and industrial chemical processes.3 It is not only abundant, inexpensive, and environmentally benign but it also shows novel reactivity and selectivity for simple synthesis of biologically active compounds in the pharmaceutical or agrochemical industries.4-7 In fact, as clearly stated by Sheldon, it is generally recognized that “the best solvent is no solvent and if a solvent is needed it should preferably be water”.8 Traditionally, organic reactions are carried out in organic solvents (e.g., THF, DMF) and oftentimes at temperatures above ambient,9 although use of (potentially toxic) organic solvents is always the norm, which by definition fails to meet the 12 Principles of Green Chemistry.10 Syntheses of polyfunctional heterocyclic fused ring systems with low molecular weight are important in life science industries.11,12 Pentafluoropyridine has attracted considerable interest due to its synthetic utility. Various multi-functional pyridine derivatives and construction of new heterocyclic and macrocyclic systems could be accessed from simple reaction conditions.13-20 These were including reaction of various 738 HETEROCYCLES, Vol. 91, No. 4, 2015