Synthesis of terephthalic acid via Diels-Alder reactions with ethylene and oxidized variants of 5-hydroxymethylfurfural

Abstract

Terephthalic acid (PTA), a monomer in the synthesis of polyethylene terephthalate (PET), is obtained by the oxidation of petroleumderived p-xylene. There is significant interest in the synthesis of renewable, biomass-derived PTA. Here, routes to PTA starting from oxidized products of 5-hydroxymethylfurfural (HMF) that can be produced from biomass are reported. These routes involve DielsAlder reactions with ethylene and avoid the hydrogenation of HMF to 2,5-dimethylfuran. Oxidized derivatives of HMF are reacted with ethylene over solid Lewis acid catalysts that do not contain strong Brønsted acids to synthesize intermediates of PTA and its equally important diester, dimethyl terephthalate (DMT). The partially oxidized HMF, 5-(hydroxymethyl)furoic acid (HMFA), is reacted with high pressure ethylene over a pure-silica molecular sieve containing framework tin (Sn-Beta) to produce the Diels-Alder dehydration product, 4-(hydroxymethyl)benzoic acid (HMBA), with 31% selectivity at 61% HMFA conversion after 6 h at 190°C. If HMFA is protected with methanol to form methyl 5-(methoxymethyl)furan-2-carboxylate (MMFC), MMFC can react with ethylene in the presence of Sn-Beta for 2 h to produce methyl 4-(methoxymethyl) benzenecarboxylate (MMBC) with 46% selectivity at 28% MMFC conversion or in the presence of a pure-silica molecular sieve containing framework zirconium (Zr-Beta) for 6 h to produce MMBC with 81% selectivity at 26% MMFC conversion. HMBA and MMBC can then be oxidized to produce PTA and DMT, respectively. When Lewis acid containing mesoporous silica (MCM-41) and amorphous silica, or Brønsted acid containing zeolites (Al-Beta), are used as catalysts, a significant decrease in selectivity/yield of the DielsAlder dehydration product is observed.cycloaddition | dehydrative aromatization | heterogeneous catalysis

Production of renewable p-xylene from 2,5-dimethylfuran via Diels–Alder cycloaddition and dehydrative aromatization reactions over silica−alumina aerogel catalysts

“…In this regard, research into the production of the commodity chemicals such as benzene, toluene, and xylenes from biomass has rapidly expanded in the past decade [3][4][5]. Especially, p-xylene is one major chemical of interest due to the increasing global consumption of terephthalic acid (TPA), used in the manufacture of plastic containers, synthetic fibers, and many other products [5][6][7][8][9][10].…”

A Facile Solid‐Phase Route to Renewable Aromatic Chemicals from Biobased Furanics

“…[5] Pacheco and Davis later explored DA aromatization of various oxidized derivatives of 5-hydroxymethylfurfural (HMF) with ethylene over Lewisacidic molecular sieves,S n-Beta in particular. [6] DA aromatization of 2-methylfuran (MF) and ethylene proved less efficient over either H-Beta or Sn-Beta, with toluene selectivities not exceeding 46 %, because MF was consumed by side reactions such as dimerization.…”

“…[8,9] Consequently,o ne has to run the aromatization reaction at either low temperature [10] or, if ethylene is the dienophile,a th igh pressure. [4][5][6] Mahmoud et al addressed the issue of DA adduct instability and furan reactivity by using am ixture of methanesulfonic acid and acetic acid anhydride to synthesize (substituted) phthalic anhydride with high selectivity at 80 8 8C. [8] In an alternative approach, we recently reported on an ew three-step strategy and dealt with this general challenge in DA aromatization by including am ild intermediate hydrogenation step of the oxabicyclic adduct 1.…”

Catalytic routes towards acrylic acid, adipic acid and ε-caprolactam starting from biorenewables

“…The direct conversion gives over 70% yield. 7,[95][96][97] The direct ammoxidation of glycerol to acrylonitrile has only seen few publications. The most noticeable came from Bañares and co-workers 98 in 2008.…”