- Photo-induced deep aerobic oxidation of alkyl aromatics
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Oxidation is a major chemical process to produce oxygenated chemicals in both nature and the chemical industry. Presently, the industrial manufacture of benzoic acids and benzene polycarboxylic acids (BPCAs) is mainly based on the deep oxidation of polyalkyl benzene, which is somewhat suffering from environmental and economical disadvantage due to the formation of ozone-depleting MeBr and corrosion hazards of production equipment. In this report, photo-induced deep aerobic oxidation of (poly)alkyl benzene to benzene (poly)carboxylic acids was developed. CeCl3 was proved to be an efficient HAT (hydrogen atom transfer) catalyst in the presence of alcohol as both hydrogen and electron shuttle. Dioxygen (O2) was found as a sole terminal oxidant. In most cases, pure products were easily isolated by simple filtration, implying large-scale implementation advantages. The reaction provides an ideal protocol to produce valuable fine chemicals from naturally abundant petroleum feedstocks. [Figure not available: see fulltext.].
- Wang, Chang-Cheng,Zhang, Guo-Xiang,Zuo, Zhi-Wei,Zeng, Rong,Zhai, Dan-Dan,Liu, Feng,Shi, Zhang-Jie
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p. 1487 - 1492
(2021/07/10)
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- METHOD FOR MANUFACTURING BENZENETETRACARBOXYLIC ACID
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By selectively hydrogenating a feedstock containing two or more hydrocarbons selected from the group consisting of tricyclic aromatic hydrocarbons having an anthracene skeleton and tricyclic aromatic hydrocarbons having a phenanthrene skeleton to 1,2,3,4,5,6,7,8-octahydro bodies using, as a hydrogenation catalyst, a catalyst containing two or more active metals selected from the group consisting of nickel, molybdenum, cobalt, and tungsten and then, by oxidizing the 1,2,3,4,5,6,7,8-octahydro body using a metal oxide, a benzenetetracarboxylic acid can be efficiently manufactured.
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Paragraph 0114
(2014/02/16)
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- PROCESS FOR PRODUCING 1,2,3,4-BENZENETETRACARBOXYLIC ACID
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A method for preparation of 1,2,3,4-benzenetetracarboxylic acid includes the step of oxidizing 1,2,3,4,5,6,7,8-octahydrophenanthrene with potassium permanganate. This method for preparation is superior to conventional methods because raw materials are easily available, special facilities are not required, and fewer reaction steps are needed. The resulting 1,2,3,4-benzenetetracarboxylic acid is useful as a raw material for functional polymers or as an intermediate of various chemicals.
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Page/Page column 5
(2009/12/28)
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- Preparation of Benzenetetracarboxylic Acids by the Cobalt-Catalyzed Carbonylation of Schiff Bases from Benzenedicarbaldehydes and Subsequent Oxidation
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Schiff bases (3a-d and 4a-c), synthesized from benzenedicarbaldehydes (terephthalaldehyde and isophthalaldehyde) and primary amines (methylamine, ethylamine, butylamine, and aniline), were carbonylated in the presence of Co2(CO)8 under an elevated pressure at 200-290 deg C to give dicarbonylated products, benzodipyrrolediones (5a-d, 10a-c, and 11a-c), in high yields. 1,2,3,4-Benzenetetracarboxylic acid (prehnitic acid) and 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid) were prepared selectively by the oxidation of the benzodipyrrolediones with nitric acid.Structu ral analysis of the benzodipyrrolediones by NMR spectra and the mechanism of the carbonylation reaction are discussed.
- Kajimoto, Tsunesuke,Tsuji, Jiro
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p. 1685 - 1690
(2007/10/02)
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