Aryl ethyl ethers prepared by ethylation using diethyl carbonate

Abstract

An environmentally more convenient reaction for the production of industrially important aryl ethyl ethers (ArOEts) is described. ArOEts were selectively obtained in essentially quantitative yields by the reaction of corresponding (hetero)aromatic alcohols (ArOHs) with diethyl carbonate as the environmentally friendly alkylating reagent in the presence of N,N-dimethylacetamide used as polar aprotic cosolvent, and sodium ethoxide as the base. The reactions were carried out in the air under atmospheric pressure at 1378C. Reaction equilibrium was shifted by distilling the ethanol from the reaction mixture. All ArOEts were isolated by evaporation of the reaction mixture, and subsequent extraction with water and diethoxymethane. The ethylation agent and used solvents were non-toxic, recyclable and biologically degradable. Wastewater from the extraction was successfully treated by Fenton oxidation and returned to the next work-up process.

C,N-chelated organotin(IV) trifluoroacetates. Instability of the mono- and diorganotin(IV) derivatives.

“…The diethyl carbonate (DEC) is a well-known non-toxic reagent and solvent that have been used for many green applications, namely the substitution of toxic reagents such as alkyl halides and phosgene for the selective alkylation and carboxyalkylation, respectively, of numerous nucleophiles [32]. The alkylation reactions of DEC with phenols normally occurred in presence of overstoichiometric amounts of base [35]. For preparation of diphenyl carbonate (DPC) from DMC and phenol various organotin(IV) compounds (such as Bu 2 SnO and Bu 2 Sn(OAc) 2 ) were tested [36].…”

Sustainable allylation of organosolv lignin with diallyl carbonate and detailed structural characterization of modified lignin

“…1 With a content of [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] wt%, lignin is a main component of biomass such as wood and annual plants. The total lignin resources on earth are estimated to be 300 billion tons, with a natural production of 20 billion tons per year.…”

A New Alkylation of Aryl Alcohols by Boron Trifluoride Etherate

“…General procedure (compound 1 [4,11]): In a 50 mL round-bottomed flask equipped with a magnetic stirring bar, a reflux condenser and a calcium chloride drying tube were placed phenol (1 g, 10.6 mmol) and boron trifluoride etherate (10 mL, 77 mmol). The reaction mixture was stirred and heated to 120 °C for four hours during which the progress of the reaction was monitored by thin layer chromatography (n-hexane/ethyl acetate 7:1).…”

“…Aryl ethyl ethers find varied applications in industry ranging from solvents, paints, cosmetics, and pharmaceuticals [2]. For example, p -ethoxyaniline is the precursor for the production of the analgesic phenacetin [3,4], β-ethoxynaphthalene (also known as nerolin) is used as a fixative in perfumery [5] while some derivatives of aryl ethers exhibit antioxidative properties [6]. In light of the aforementioned properties of aryl ethyl ethers and their potential applications in the chemical and pharmaceutical industries, we set out to explore the alkylation of various phenols using this new ethylating agent.…”

“…However the resultant triphenylphosphine oxide poses tremendous challenges during product purification. Recently, an alternative version of the Williamson ether synthesis using dialkyl carbonates and imidazole carbamates as the alkylating agents [4,15,16,17] has been proposed. Because BTE is mostly used as catalyst at low temperatures, its capacity to act as an alkylating agent has eluded the attention of organic chemists until now.…”