Cyclohexanone, from cyclohexane

Oxidation of organic compounds by dioxygen is a phenomenon of exceptional importance in nature, technology, and life. The liquid-phase oxidation of hydrocarbons forms the basis of several efficient technological synthetic processes such as the production of phenol via cumene oxidation, cyclohexanone from cyclohexane, styrene oxide from ethylbenzene, etc. The intensive development of oxidative petrochemical processes was observed in 1950-1970. Free radicals participate in the oxidation of organic compounds. Oxidation occurs very often as a chain reaction. Hydroperoxides are formed as intermediates and accelerate oxidation. The chemistry of the liquid-phase oxidation of organic compounds is closely interwoven with free radical chemistry, chemistry of peroxides, kinetics of chain reactions, and polymer chemistry. 

Cyclopol A process for making cyclohexanone from benzene, the intermediates being cyclohexane and cyclohexanol. Developed and licensed by Polimex-Cekop. In 1997,20 percent of world demand for cyclohexanone was made by this process. 

Sun, H., Blatter, F. and Frei, H. (1996). Cyclohexanone from cyclohexane and 02 in a zeolite under visible light with complete selectivity. J. Am. Chem. Soc. 118, 6873-6879... 

Capello et al.16 applied LCA to 26 organic solvents (acetic acid, acetone, acetonitrile, butanol, butyl acetate, cyclohexane, cyclohexanone, diethyl ether, dioxane, dimethylformamide, ethanol, ethyl acetate, ethyl benzene, formaldehyde, formic acid, heptane, hexane, methyl ethyl ketone, methanol, methyl acetate, pentane, n- and isopropanol, tetrahydrofuran, toluene, and xylene). They applied the EHS Excel Tool36 to identify potential hazards resulting from the application of these substances. It was used to assess these compounds with respect to nine effect categories release potential, fire/explosion, reaction/decomposition, acute toxicity, irritation, chronic toxicity, persistency, air hazard, and water hazard. For each effect category, an index between zero and one was calculated, resulting in an overall score between zero and nine for each chemical. Figure 18.12 shows the life cycle model used by Capello et al.16... 

Cyclohexanol and cyclohexanone from cyclohexane with supported Co (s) as the catalyst. 

Molecular oxygen can also oxidize a variety of organic compounds, including hydrocarbons, aldehydes, amines, ethers and ketones. These autooxidation reactions can be used to make a variety of small molecules and a number of industrial processes rely on the controlled oxidation of organics using molecular oxygen (often with a metal catalyst). Examples include the formation of phenol and acetone from cumene (isopropylbenzene) and cyclohexanone from cyclohexane. Phenol is a popular starting material for a number... 

Caprolactam (world production of which is about 5 million tons) is mostly produced from benzene through three intermediates cyclohexane, cyclohexanone and cyclohexanone oxime. Cyclohexanone is mainly produced by oxidation of cyclohexane with air, but a small part of it is obtained by hydrogenation of phenol. It can be also produced through selective hydrogenation of benzene to cyclohexene, subsequent hydration of cyclohexene and dehydrogenation of cyclohexanol. The route via cyclohexene has been commercialized by the Asahi Chemical Company in Japan for adipic acid manufacturing, but the process has not yet been applied for caprolactam production. 

Adipic acid can also be obtained from cyclohexane extracted from petroleum, or manufactured by catalytic reduction of benzene. The cyclohexane is oxidized with air in the presence of copper or cobalt, which act as catalysts, to give a mixture of cyclohexanol and cyclohexanone, both of... 

Polyamides. The first commercially produced synthetic polyamides were made from dibasic acids and diamines exemplified by polyhexameth-ylene adipamide (6,6-nylon). Adipic acid was first commercially produced by osdation of cyclohexanone produced from phenol, but today it is largely produced by oxidation of cyclohexane derived from either benzene or petroleum. Sebacic acid, another important nylon intermediate, is produced by caustic oxidation of ricinoleic acid from castor oil. 

Using the rigid-rotor harmonic-oscillator approximation on the basis of molecular constants and the enthalpies of formation, the thermodynamic functions C°p, S°, — G° —H°o)/T, H° — H°o, and the properties of formation Af<7°, and log K°(to 1500 K in the ideal gas state at a pressure of 1 bar, were calculated at 298.15 K and are given in Table 9 <1992MI121, 1995MI1351>. Unfortunately, no experimental or theoretical data are available for comparison. From the equation log i = 30.25 - 3.38 x /p t, derived from known reactivities (log k) and ionization potential (fpot) of cyclohexane, cyclohexanone, 1,4-cyclohexadiene, cyclohexene, 1,4-dioxane, and piperidine, the ionization potential of 2,4,6-trimethyl-l,3,5-trioxane was calculated to be 8.95 eV <1987DOK1411>. 

Figure 11 Pyrolysis of cyclohexanone-formaldehyde resins at 650°C for 5 s showing differences due to source and ageing. Identified peaks are 1 = cyclohexene 3=cyclohexanone 4= 2-methylcyclohexanone 5 = 2-methylenecyclohexanone 8= 2-methyl-6-methylenecyclohexanone 9 = 2,6-dimethylenecyclo-hexanone peaks 22-44 correspond to products with two or three cyclohexane residues. (From Mestdagh H, Rolando C, and Sablier M (1992) Analytical Chemistry 64 2221-2226.)...

Caprolactam can be made in a large number of ways. One method that is used commercially involves oxidation of cyclohexane to cyclohexanone, from which the oxime is made. This oxime reacts by the Beckmann reananganent to give caprolactam. The polymerization of caprolactam is carried out by adding water to open the rings and then removing the water again at elevated temperature, where linear polymer forms. An autoclave or a continuous reactor can be used. 

The ultraviolet absorption spectrum of cyclohexanone reflects the n jt transition common to all carbonyls see figure IX-E-1. The data derived from gas-phase measurements of the cross sections for cyclohexanone from two different research groups [National Center for Atmospheric Research (NCAR) and Ford Scientific Laboratories (Ford)] are in reasonable agreement (Iwasaki et al., 2008). The cyclohexanone cross sections as measured in cyclohexane solution by Benson and Kistiakowski (1942) had indicated seemingly low values (cross sections shown here is significantly less than those observed for cyclopropanone, cyclobutanone, and cyclopentanone, and in fact, all other carbonyls considered in this work. It is not obvious why these significant differences exist in the probability for the n -> 7T transition for cyclohexanone and that of the other cyclic ketones and most other carbonyl compounds. Theoretical studies will be important in defining the reasons for these differences. 

Beckmann rearrangement of cvc7ohexanone oxime. M.p. 68-70 C, b.p. I39 C/12 mm. On healing it gives polyamides. Used in the manufacture of Nylon[6]. Cyclohexanone oxime is formed from cyclohexane and niirosyl chloride. U.S. production 1978 410 000 tonnes, capryl alcohol See 2-octanol. caiH Uc acid See oclanoic acid. 

Since adipic acid has been produced in commercial quantities for almost 50 years, it is not surprising that many variations and improvements have been made to the basic cyclohexane process. In general, however, the commercially important processes stiU employ two major reaction stages. The first reaction stage is the production of the intermediates cyclohexanone [108-94-1] and cyclohexanol [108-93-0], usuaHy abbreviated as KA, KA oil, ol-one, or anone-anol. The KA (ketone, alcohol), after separation from unreacted cyclohexane (which is recycled) and reaction by-products, is then converted to adipic acid by oxidation with nitric acid. An important alternative to this use of KA is its use as an intermediate in the manufacture of caprolactam, the monomer for production of nylon-6 [25038-54-4]. The latter use of KA predominates by a substantial margin on a worldwide basis, but not in the United States. 

Cyclohexane. The LPO of cyclohexane [110-82-7] suppUes much of the raw materials needed for nylon-6 and nylon-6,6 production. Cyclohexanol (A) and cyclohexanone (K) maybe produced selectively by using alow conversion process with multiple stages (228—232). The reasons for low conversion and multiple stages (an approach to plug-flow operation) are apparent from Eigure 2. Several catalysts have been reported. The selectivity to A as well as the overall process efficiency can be improved by using boric acid (2,232,233). K/A mixtures are usually oxidized by nitric acid in a second step to adipic acid (233) (see Cyclohexanol and cyclohexanone). 

Another synthesis of pyrogaHol is hydrolysis of cyclohexane-l,2,3-trione-l,3-dioxime derived from cyclohexanone and sodium nitrite (16). The dehydrogenation of cyclohexane-1,2,3-triol over platinum-group metal catalysts has been reported (17) (see Platinum-GROUP metals). Other catalysts, such as nickel, rhenium, and silver, have also been claimed for this reaction (18). 

Caprolactam [105-60-2] (2-oxohexamethyleiiiiriiQe, liexaliydro-2J -a2epin-2-one) is one of the most widely used chemical intermediates. However, almost all of the aimual production of 3.0 x 10 t is consumed as the monomer for nylon-6 fibers and plastics (see Fibers survey Polyamides, plastics). Cyclohexanone, which is the most common organic precursor of caprolactam, is made from benzene by either phenol hydrogenation or cyclohexane oxidation (see Cyclohexanoland cyclohexanone). Reaction with ammonia-derived hydroxjlamine forms cyclohexanone oxime, which undergoes molecular rearrangement to the seven-membered ring S-caprolactam. 

BASF. In the Badische process, cyclohexanone is produced by Hquid-phase catalytic air oxidation of cyclohexane to KA oil, which is a mixture of cyclohexanone and cyclohexanol, and is followed by vapor-phase catalytic dehydrogenation of the cyclohexanol in the mixture. Overall yields range from 75% at 10% cyclohexane conversion to 80% at 5% cyclohexane conversion. 

Toray. The photonitrosation of cyclohexane or PNC process results in the direct conversion of cyclohexane to cyclohexanone oxime hydrochloride by reaction with nitrosyl chloride in the presence of uv light (15) (see Photochemical technology). Beckmann rearrangement of the cyclohexanone oxime hydrochloride in oleum results in the evolution of HCl, which is recycled to form NOCl by reaction with nitrosylsulfuric acid. The latter is produced by conventional absorption of NO from ammonia oxidation in oleum. Neutralization of the rearrangement mass with ammonia yields 1.7 kg ammonium sulfate per kilogram of caprolactam. Purification is by vacuum distillation. The novel chemistry is as follows ... 

A route to phenol has been developed starting from cyclohexane, which is first oxidised to a mixture of cyclohexanol and cyclohexanone. In one process the oxidation is carried out in the liquid phase using cobalt naphthenate as catalyst. The cyclohexanone present may be converted to cyclohexanol, in this case the desired intermediate, by catalytic hydrogenation. The cyclohexanol is converted to phenol by a catalytic process using selenium or with palladium on charcoal. The hydrogen produced in this process may be used in the conversion of cyclohexanone to cyclohexanol. It also may be used in the conversion of benzene to cyclohexane in processes where benzene is used as the precursor of the cyclohexane. 

The reaction of enamines derived from cyclohexanone with dichlorocarbene to give the 1 1 adducts is now well established (137-139). The morpholine enamine (113) reacted with dichlorocarbene at —10 to —20° in tetrahydrofuran to give the stable crystalline adduct (201). Thermal decomposition followed by an aqueous work-up gave an a,)3-unsaturated ketone identified as 2-chloromethylene-cyclohexan-l-one (202) (139). 

Recendy, Darzens reaction was investigated for its synthetic applicability to the condensation of substituted cyclohexanes and optically active a-chloroesters (derived from (-)-phenylmenthol). In this report, it was found that reaction between chloroester 44 and cyclohexanone 43 provided an 84% yield with 78 22 selectivity for the axial glycidic ester 45 over equatorial glycidic ester 46 both having the R configuration at the epoxide stereocenter. 

Using different mono- and diketones in acetic acid (at room temperature) afforded the following products from benzophenone, 2,2-diphenyl-2//-imid-azo[4,5-/]quinoline from dibenzylketone, the 2-benzyl-imidazo[4,5-/]quino-line and from 2,4-pentanedione, 2-methyl-imidazo[4,5-/]quinoline. Cyclohexanone under reflux gave 2-n-pentyl-, whereas at room temperature it afforded the. s pira[cyclohexane-l,2 ]-(2//)-imidazo[4,5-/]quinoline 108 (R R =(CFl2)5) (86UC527). 

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