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Dimethyl oxalate can be converted into ethylene glycol in high yields (94.7%) [10] [11] The methanol formed is recycled in the process of oxidative carbonylation. [12] Other plants with a total annual capacity of more than 1 million tons of ethylene glycol per year are planned. Decarbonylation gives dimethyl carbonate. [13]
Oxalate (systematic IUPAC name: ethanedioate) is an anion with the chemical formula C 2 O 2− 4. This dianion is colorless. It occurs naturally, including in some foods. It forms a variety of salts, for example sodium oxalate (Na 2 C 2 O 4), and several esters such as dimethyl oxalate ((CH 3) 2 C 2 O 4). It is a conjugate base of oxalic acid.
Synthesis of acrylic acid using "Reppe chemistry"; a metal catalyst is required. The carbomethoxylation of ethylene to give methyl propionate: C 2 H 4 + CO + MeOH → MeO 2 CC 2 H 5. Methyl propionate ester is a precursor to methyl methacrylate. [10] Hydroesterification is like hydrocarboxylation, but it uses alcohols in place of water. [11]
Another process uses oxygen to regenerate the nitric acid, using a variety of precursors including glycolic acid and ethylene glycol. [17] As of 2011, this process was only used by Mitsubishi in Japan. [18] A newer method entails oxidative carbonylation of alcohols to give the diesters of oxalic acid: 4 ROH + 4 CO + O 2 → 2 (CO 2 R) 2 + 2 H 2 O
ODAP can be synthesized from L-α,β-diaminopropionic acid and dimethyl oxalate at a pH of 4.5-5. Cupric oxide can be used to temporarily protect the α-NH2 group of the L-α,β-diaminoproprionic acid during the reaction. [2] The pathway for one chemical synthesis of ODAP
Oxidative carbonylation is a class of reactions that use carbon monoxide in combination with an oxidant to generate esters and carbonate esters.These transformations utilize transition metal complexes as homogeneous catalysts. [1]
The natural process of aging. Diagnosing sarcopenia is not straightforward, but may involve physical tests. These can include testing hand grip strength, measuring walking speed, or using the ...
The first step of the synthesis is the condensation of o-nitrotoluene 1 with a diethyl oxalate 2 to give ethyl o-nitrophenylpyruvate 3. The reductive cyclization of 3 with zinc in acetic acid gives indole-2-carboxylic acid 4. If desired, 4 can be decarboxylated with heat to give indole 5.