Cyclohexane, conversion Into

The solid is used as a heterogeneous catalyst or as a water-soluble system in biphasic conditions in the hydrogenation of benzene and pheny-lacetylene [65]. The heterogeneous system Rh-PVP is investigated in the solid/liquid catalytic hydrogenation of benzene with a ratio of 1/34000 at 80 °C and 20 bar H2. The conversion into cyclohexane is about 60% after 200 h of reaction time. In a water/benzene biphasic condition at 30 °C and under 7 bar H2, complete hydrogenation (Scheme 2) for a molar ratio of 2000 is observed after 8 h giving a TOF = 675 h (related to H2 consumed), never-... 

A recent stndy (13,27) describes the use of Co-Si-TUD-1 for the liquid-phase oxidation of cyclohexane. Several other metals were tested as well. TBHP (tert-butyl hydroperoxide) was used as an oxidant and the reactions were carried out at 70°C. Oxidation of cyclohexane was carried out using 20 ml of a mixture of cyclohexane, 35mol% TBHP and 1 g of chlorobenzene as internal standard, in combination with the catalyst (0.1 mmol of active metal pretreated overnight at 180°C). Identification of the products was carried out using GC-MS. The concentration of carboxylic side products was determined by GC analysis from separate samples after conversion into the respective methyl esters. Evolution and consumption of molecular oxygen was monitored volumetrically with an attached gas burette. All mass balances were 92% or better. 

The fluorination of cyclohexane probably takes place via an initial conversion into benzene, brought about by the fluorinating agent, as under certain conditions (CeF4 at 300 C, a temperature at which benzene does not fluorinate over this reagent) benzene can be isolated as the near-sole product.42 If cyclohexane is first converted into benzene, then all fluorinations of saturated compounds might also proceed via an initial desaturation step this point is touched on several times throughout Section 25.1. The products are much the same as those obtained from benzene (Section 25.1.1.2.). 

Another interesting ozonolysis reaction is summarized by the conversion of 2-(2 -cyanoethyl)-l-(benzyloxymethyl-ene)cyclohexane 76 into 1,2-dioxepane (trioxane) 77 the experimental section cites a 92% yield (Equation 18) <2002JME3824, 2000BMC1361>. 

Similarly, cyclohexane is readily oxidized by cobalt(III) acetate in acetic acid at moderate temperatures.29Sa d In the absence of oxygen at 80°C the main products were 2-acetoxycyclohexanone and cyclohexyl acetate. Cyclohexane was about half as reactive as toluene under these conditions. Oxidation with Co(III) acetate in the presence of oxygen gave adipic acid as the main product. This reaction has been developed into a process for the single-stage oxidation of cyclohexane to adipic acid.296,297 Selectivities of approximately 75% have been claimed at roughly 80% cyclohexane conversion. 

Synthons such as 237 or 238 might appear to be non-productive as the availability of reagents corresponding to these synthons may be questionable. Nevertheless, if one takes into account the options to synthesize p-substituted aromatic compounds and their ease of conversion into ci, s -l,4-disubstituted cyclohexanes via catalytic hydrogenation), the proposed disconnections become immediately feasible. This reasoning leads to routes A and B as realistic pathways for the preparation of 236. 

Tavs, P, Synthesis of fra i-ethylene-l,2-diphosphonic acid esters and conversion into cyclohexane-1.2-diphosphonic acid, Chem. Ber., 100, 1571, 1967. 

Azomethane imines undergo an analogous photoinduced cyclization to give diaziridines. The dihydroisoquinoline derivative (99), for example, is converted on irradiation in cyclohexane or benzene into the diaziridine (100) the transformation is thermally reversible. In contrast, the pyrazolidinone azomethine imines (101) undergo photoreversible conversion into the diaziridines (102), providing in this way a useful reversible photochromic system. The analogous photoisomerization of a pyrene-substituted pyrazolidinone azomethinimine has... 

The encapsulation of metalloporphyrins in the cavities of an indium imidazoledicarboxylate-based rho-zeolite-like metal-organic framework (rho-ZMOF) has been reported by Eddaoudi and coworkers [71]. The catalytic activity of this material was assessed by cyclohexane oxidation with TBHP as the oxidant, with cyclohexane conversion reaching 91.5% after 24 h at 65 °C. Cyclohexanol and cyclohexanone were the only observed products, suggesting that the investigated oxidation reaction is selective toward the desired products. Furthermore, upon reuse of the catalyst, no loss of crystaUinity, reactivity, and selectivity in up to 11 cycles was observed, while no leaching of the encapsulated metalloporphyrin into the product solution was detected by the UV-vis spectra. 

Olefins reacted with 5-phenyl-l,2,4-dithiazole-3-thiones when irradiated to give 1,3-dithiolan derivatives, cyclohexene for example giving (150), which on acid hydrolysis unexpectedly gave (151). The m-fusion of the rings in (151) was established by its conversion into cyclohexene on treatment with triethyl phosphite. Olefins with electron-withdrawing substituents did not react with 5-phenyl-l,2,4-dithiazole-3-thione, suggesting that free-radical intermediates, and not 1,3-dipolar intermediates, were involved in the initial addition. The hitherto unknown l,3-dithiolan-4-thione system has been synthesized cyclohexane-1,1-dithiol reacted... 

Hydroperoxide Process. The hydroperoxide process to propylene oxide involves the basic steps of oxidation of an organic to its hydroperoxide, epoxidation of propylene with the hydroperoxide, purification of the propylene oxide, and conversion of the coproduct alcohol to a useful product for sale. Incorporated into the process are various purification, concentration, and recycle methods to maximize product yields and minimize operating expenses. Commercially, two processes are used. The coproducts are / fZ-butanol, which is converted to methyl tert-huty ether [1634-04-4] (MTBE), and 1-phenyl ethanol, converted to styrene [100-42-5]. The coproducts are produced in a weight ratio of 3—4 1 / fZ-butanol/propylene oxide and 2.4 1 styrene/propylene oxide, respectively. These processes use isobutane (see Hydrocarbons) and ethylbenzene (qv), respectively, to produce the hydroperoxide. Other processes have been proposed based on cyclohexane where aniline is the final coproduct, or on cumene (qv) where a-methyl styrene is the final coproduct. 

The total hydrogenation of benzene derivatives represents an important industrial catalytic transformation, in particular with the conversion of benzene into cyclohexane, a key intermediate in adipic acid synthesis, which is used in the production of Nylon-6,6 (Scheme 1). This reaction is still the most important industrial hydrogenation reaction of monocyclic arenes [1]. 

Nitration of ketones or enol ethers provides a useful method for the preparation of a-nitro ketones. Direct nitration of ketones with HN03 suffers from the formation of a variety of oxidative by-products. Alternatively, the conversion of ketones into their enolates, enol acetates, or enol ethers, followed by nitration with conventional nitrating agents such as acyl nitrates, gives a-nitro ketones (see Ref. 79, a 1980 review). The nitration of enol acetates of alkylated cyclohexanones with concentrated nitric acid in acetic anhydride at 15-22 °C leads to mixtures of cis- and rrans-substituted 2-nitrocyclohexanones in 75-92% yield. 4-Monoalkylated acetoxy-cyclohexanes give mainly m-compounds, and 3-monoalkylated ones yield fra/w-compounds (Eq. 2.40).80... 

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