Efficient Syntheses of Biobased Terephthalic Acid, p-Toluic Acid, and p-Methylacetophenone via One-Pot Catalytic Aerobic Oxidation of Monoterpene Derived Bio-p-cymene

Abstract

An efficient elevated-pressure catalytic oxidative process (2.5 mol % Co(NO 3 ) 2 , 2.5 mol % MnBr 2 , air (30 bar), 125 °C, acetic acid, 6 h) has been developed to oxidize p -cymene into crystalline white terephthalic acid (TA) in ∼70% yield. Use of this mixed Co 2+ /Mn 2+ catalytic system is key to obtaining high 70% yields of TA at relatively low reaction temperatures (125 °C) in short reaction times (6 h), which is likely to be due to the synergistic action of bromine and nitrate radicals in the oxidative process. Recycling studies have demonstrated that the mixed metal catalysts present in recovered mother liquors could be recycled three times in successive p -cymene oxidation reactions with no loss in catalytic activity or TA yield. Partial oxidation of p -cymene to give p -methylacetophenone ( p -MA) in 55–60% yield can be achieved using a mixed CoBr 2 /Mn(OAc) 2 catalytic system under 1 atm air for 24 h, while use of Co(NO 3 ) 2 /MnBr 2 under 1 atm O 2 for 24 h gave p -toluic acid in 55–60% yield. Therefore, access to these simple catalytic aerobic conditions enables multiple biorenewable bulk terpene feedstocks (e.g., crude sulfate turpentine, turpentine, cineole, and limonene) to be converted into synthetically useful bio- p -MA, bio- p -toluic acid, and bio-TA (and hence bio-polyethylene terephthalate) as part of a terpene based biorefinery.

Progress in the biosynthesis of bio-based PET and PEF polyester monomers

“…The catalyst is also recyclable and can be recycled thrice without loss of catalytic activity or TPA yield. 21…”

“…The catalyst is also recyclable and can be recycled thrice without loss of catalytic activity or TPA yield. 21 Although the above-mentioned chemical-catalytic production of TPA has largely met the needs of industrialisation, there is an urgent need to develop green processes for the sustainable production of TPA due to its environmentally harmful nature and unsustainability. For example, depolymerizing PET to recover TPA and its derivatives.…”

Conversion of Lignocellulose for Bioethanol Production, Applied in Bio-Polyethylene Terephthalate

“…Acetic acid and bromide compounds (hydrogen bromide, bromine, or tetrabromoethane) are added to the reactor as the solvent and additional oxidation agents. Tibbetts et al reported an efficient elevated-pressure catalytic oxidative process (2.5 mol% Co(NO 3 ) 2 , 2.5 mol% MnBr 2 , air (30 bar), 125 • C, acetic acid, 6 h) to oxidize p-cymene into crystalline white terephthalic acid (TA) in~70% yield [192]. On the other hand, bio-TPA can be derived from furan, for instance, 2,5-furan dicarboxylic acid (FDCA).…”

A critical review of the production of hydroxyaromatic carboxylic acids as a sustainable method for chemical utilisation and fixation of CO2

“…One group of CO 2 -based chemicals with potential high future demands are HACAs, due to the versatility of their possible uses and applications. Notable HACAs include salicylic acids, hydroxynapthoic acids and various halogenated derivatives that may be employed as intermediates or starting material in the pharmaceutical [14][15][16], dye [17,18], fragrance [19], cosmetic [20,21], food [21,22] and bioplastic industry [23][24][25]. Currently, commercial quantities of HACAs are produced via the Kolbe-Schmitt reaction between phenolic compounds and CO 2 .…”

“…Notable HACAs include salicylic acids, hydroxynaphthoic acids and various halogenated derivatives that may be employed as intermediates or starting materials in the pharmaceutical, 14–16 dye, 17,18 fragrance, 19 cosmetic, 20,21 food 21,22 and bioplastic industries. 23–25 Currently, commercial quantities of HACAs are produced via the Kolbe–Schmitt reaction between phenolic compounds and CO 2 . Thus, increasing the production, uses and applications of HACAs can contribute to increased CO 2 utilisation and long-term CO 2 sequestration.…”