Cyclohexanol succinate

Benzene, propyl acetate, allyl acetate, 1-pentanol, cyclohexanone, cyclohexanol, dicyclohexyl ether, cyclohexyl valerate, butyric acid, valeric acid, caproic acid, 1,5-pentanediol, dicyclohexyl succinate, and dicyclohexyl glutarate 30 m DB-FFAP column, 60-200° at 67min. 

Adipic acid has been prepared by the following methods the action of silver1 or copper 2 on /3-iodopropionic acid the reduction of mucic add with phosphorus and iodine 3 the electrolysis of the potassium or sodium salts of monoethyl succinate 4 the condensation of ethylene chloride or bromide with malonic ester or cyanoacetic ester and subsequent hydrolysis 5 the oxidation of certain fractions of Baku petroleum 6 the oxidation of cyclohexanol or cyclohexanone with nitric acid 7 or potassium permanganate.8... 

BA BuE-PA BE-HET BE-HHPA BE-MA BE-PA BE-SA CA CHX DMA DMBA DY 062 GA HEB HHPA HMTA MA MTHPA NMA benzoic acid monobutylester of phthalic acid monobenzylester of hexachloroendomethylenetetrahydrophthalic acid monobenzylester of hexahydrophthalic acid monobenzylester of maleic acid monobenzylester of phthalic acid monobenzylester of succinic acid citraconic anhydride cyclohexanol N,N-dimethylaniline dimethylbenzylamine high boiling tertiary amine (Ciba Geigy AG) gjptaric anhydride 2-hydroxy-4-(2,3-epoxypropoxy)benzophenone hexahydrophthalic anhydride hexamethylenetetramine maleic anhydride methyltetrahydrophthalic anhydride nadic methyl anhydride (methylbicyclo[2.2.1]heptene-2,3-dicarboxylic anhydride isomers)... 

The best result reported in the open literature is of 73% conversion with 73% selectivity to AA, obtained at normal O2 pressure, in acetic acid with 1 mol% Mn (acac)2, the by-products being glutaric acid (9%), succinic acid (6%), cyclohexyl acetate (2%) and cyclohexanol (1%) [30bj. The generation of the PINO from NHPI (Scheme 7.7) with oxygen is assisted by the Co(II) species therefore, the addition of a small amount of Co (O Ac) 2 enhances the oxidation process. In contrast, if the reaction is performed in an acetonitrile solvent, with a Co(OAc)2 catalyst at 75 °C, the main product is cyclohexanone (78% selectivity at 13% cyclohexane conversion). 

The reaction mixture (2 g) was esterified at reflux with methanol (15 cm ) in the presence of 2 drops of concentrated H2SO4 to obtain the diacids in the diesters form. The products were analysed using a Hewlett Packard gas chromatograph equipped with a Carbowax 52 CB polar capillary column and a flame ionization detector assembled with a Shimadzu programmed and computerized Chromatopac CR6A. The reaction products consisted of adipic, glutaric, succinic and 6-hydroxycaproic acids, cyclohexanone, cyclohexanol and butyrolactone. 

About 5 billion pounds per year of adipic acid are manufactured worldwide by the nitric acid oxidation of cyclohexanone and/or cyclohexanol (KA). The KA to adipic acid yields are near 94% of theory. Glutaric and succinic acids are the major byproducts and account for most of the yield loss. Monsanto and some other adipic acid producers recover or upgrade these to salable b products resulting in an overall KA utilization efiflciency that approaches 99%. However, the nitric acid efficiency is lower because approximately 1 mole N2O is produced per mole of adipic acid, in addition to the easily recyclable NOx that is generated as a result of nitric acid reduction. 

When this method is applied to cyclohexanone, it produces a mixture of 50% adipic acid, 19% glutaric acid, and 3% succinic acid. Further work is needed to steer the reaction to a high yield of the desired adipic acid. A chromium aluminum phosphate molecular sieve has been used with oxygen and a catalytic amount of a hydroperoxide to convert cyclohexane to a mixture of 48% cyclohexanone, 5% cyclohexanol, 6% cyclohexanehydroperoxide, and 40% adipic acid, at 10% conversion. The catalyst could be reused four times without loss of activity.205 Presumably, the products other than adipic acid could be recycled to the next run. The authors do not give the selectivity at higher conversions. Ideally, one would like a similar system that would give only adipic acid at 100% conversion. 

Waste or byproduct organic acids could be cost-effective alternatives. Adipic acid production by nitric acid oxidation of cyclohexanol/cyclohexanone generates byproduct consisting of glutaric and succinic acids which should perform like adipic acid. Air oxidation of cyclohexane to produce cyclohexanone as an intermediate for caprolactam generates a waste solution of adipic, hydroxyvaleric, glutaric, and other acids. This product should be comparable to a mixture of adipic and hydroxypropionic acids. 

Purification of these oxidation products of cyclohexane for the second-stage nitric acid oxidation to adipic acid is not necessary but is advantageous from the viewpoint of yield and purity of product. The preferred commercial practice is to treat the product obtained by air oxidation of ( cldhexane in pressure autoclaves with a controlled amount of water to permit an oil-water separation. The cyclohexanol and cyclohexanone dissolved in the water phase are removed by steam distillation and added to the oil phase. Succinic and glutaric acids which occur as by-products are recovered from the water phase. The combined oil is stripped to remove dissolved cyclohexane for recycle to the stage 1 air oxidation. The oil is then steam distilled and freed of water. ... 

Initially, cyclohexane is oxidized to the intermediate cyclohexyl hydroperoxide, CHHP. Then, the obtained CHHP is decomposed into the desired components cyclohexanone and cyclohexanol however, it is also partly decomposed into undesired by-products. A part of the formed cyclohexanol is further oxidized to cyclohexanone and a part of the formed cyclohexanone is converted to by-products. Part of the cyclohexane oxidation by-products are further destroyed (not shown in this figure). The by-products finally obtained include, in various amounts, acids such as adipic acid, e-hydroxycaproic acid, glutaric acid, succinic acid, valeric acid, caproic acid, propionic acid, acetic acid, formic acid, and noncondensable gases such as CO and CO2. In addition, several esters are formed between mainly cyclohexanol and the various carboxylic acids. The destinations of these by-products are quite diverse and depend on the producer for example, some of these byproducts are fed to combustion units for heat recovery purposes, while others are used as feedstock for chemicals such as 1,5-pentanediol, 1,6-hexanediol (HDO), and caprolactone. In general cyclohexanol is recovered from esters in a biphasic saponification step. 

Although air oxidation of the cyclohexanone-cyclohexanol mixtures on a Cu-Mn catalyst in acetic acid [140] is possible, the principal commercial operations entail oxidation with nitric acid. The reaction is usually carried out at 60 80°C and pressures of 0.1 to 0.4 MPa, employing 50-60% nitric acid and a copper-vanadium catalyst containing between 0.1 and 0.5% Cu and 0.1 and 0.2% V [141]. The yields of adipic acid are in the range of 90-96%. The main by-products are succinic acid and glutaric acid. Their concentration generally increases as the purity of the feed mixture decreases. The adipic acid is isolated by crystallization and purified by recrystallization from water. 

Cyclohexanol Cyclohexanone 3,4-Dichlorobenzotrifluoride DIethylene glycol dibutyl ether Dimethyl adipate Dimethyl glutarate Dimethyl succinate Dipropylene glycol butyl ether Dipropylene glycol t-butyl ether Dipropylene glycol ethyl ether... 

In accordance with the above reaction mechanism and under the simplifying assumption that cyclohexanol is the oidy raw material used, for each mol of alcohol, two moles of ititric acid are reduced to nitrous oxide, with a specific consumption of 0.863 kg HNOs/kg AA and 100% selectivity. In practice, however, reaction selectivity is lower because of the formation of glutaric and succinic acids and CO2, which raises the specific consumption above the stoichiometric value (for 95% selectivity, the consumption is 0.908 kg HN03/kg AA). This is the actual consumption, since the quantity of nitric acid used in the reaction is in reality greater. However, the excess nitric acid leads to the formation of higher nitrogen oxides (NO and NO2), which can be recovered by absorption in water and converted back to nitric acid, which can then be recycled into the process. 

---