Cydohexanol mixtures

The efficacy of GC separations is highly dependent on the experimental conditions. For example, two sets of experimental data on the heptanal-cydohexanol mixture are given below to demonstrate the effects of variations in oven temperature on retention times. 

In a 1500 ml. round-bottomed flask, carrying a reflux condenser, place 100 g. of pure cydohexanol, 250 ml. of concentrated hydrochloric acid and 80 g. of anhydrous calcium chloride heat the mixture on a boiling water bath for 10 hours with occasional shaking (1). Some hydrogen chloride is evolved, consequently the preparation should be conducted in the fume cupboard. Separate the upper layer from the cold reaction product, wash it successively with saturated salt solution, saturated sodium bicarbonate solution, saturated salt solution, and dry the crude cycZohexyl chloride with excess of anhydrous calcium chloride for at least 24 hours. Distil from a 150 ml. Claisen flask with fractionating side arm, and collect the pure product at 141-5-142-5°. The yield is 90 g. 

When camphene reacts with guaiacol (2-methoxyphenol), a mixture of terpenyl phenols is formed. Hydrogenation of the mixture results in hydrogenolysis of the methoxy group and gives a complex mixture of terpenyl cydohexanols (eg, 3-(2-isocamphyl) cyclohexanol [70955-714] (45)), which after fractional distillation produces a useful sandalwood fragrance product (85). A similar process has also been developed using catechol and camphene (86). 

Hydrocarbon Oxidation. The oxidation of hydrocarbons (qv) and hydrocarbon derivatives can be significantly altered by boron compounds. Several large-scale commercial processes, such as the oxidation of cyclohexane to a cydohexanol—cyclohexanone mixture in nylon manufacture, are based on boron compounds (see Cylcohexanol and cyclohexanone Fibers, polyamide). A number of patents have been issued on the use of borate esters and boroxines in hydrocarbon oxidation reactions, but commercial processes apparently use boric acid as the preferred boron source. The literature in this field has been covered through 1967 (47). Since that time the literature consists of foreign patents, but no significant applications have been reported for borate esters. 

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

The alkene mixture obtained on dehydration of 2,2-dimethyl-cydohexanol contains appreciable amounts of 1,2-dimethylcydohexene. Give a mechanistic explanation for the formation of this product. 

The column (C-3) delivers cydohexanol as top and a phenol/cyclohexanol mixture to be recycled as bottoms. The column is designed to ensure bottoms as close as possible to the azeotrope phenol/cyclohexanol, while minimizing losses in cyclohexanone. This column has 30 theoretical stages and operates at moderate reflux, below 3 1, which leads to diameters of 2.5/1.8m. 

These processes involve two stages. Cyclohexane is first oxidized to a cydohexanol/ cyclohexanone mixture (see Section 9.1.6.1 and Section 121.22X which is then dehydrogenated (Fig. 121IX This Ol/One mixture is first fractionated in a series of three distillation columns operating under vacuum, of which the first two (20 trays each) separate the... 

Fig. 1211. Cyclohexanone production from cyclohexane. Dehydrogenation of cydohexanol/cyciohexanone mixture.

Z)-2-Aceto y-l-[(/R, 2R )-trans-2-le l-butyldimetliylsilyloxy-l-cyclohexy/oxy]-l-buten-3-one A solution of 1.8 g (11.4 mmol) of tr n.r-3-acetoxy-4-methoxy-3-buten-2-one, 2.4 g (10.4 mmol) of ( R, 2R )-trans-2-rm-butyldimethylsilyloxy-1-cydohexanol obtained above, and 0.3 g (1.2 mmol) of pyridinium 4-toluene-sulfonate in 50 mL of benzene is refluxed for 30 h with continuous removal of CH, OH using a Dean-Stark trap containing 4 A molecular sieves. The reaction mixture is concentrated in vacuo and chromatographed (silica gel, EtOAc/hexane 3 7) yield 2.6 g (70%). 

Another in situ preparation of molecularly imprinted columns employs dispersion polymerization, whereby agglomerated polymer particles are obtained [53]. The procedure is similar to the rod preparation a mixture of the chemicals for the polymer preparation, such as a template, a functional monomer, a crosslinker, a porogen and an initiator is placed in a column and heated to cause polymerization. This method also requires polar solvents, such as cydohexanol-dodecanol and isopropanol-water, to obtain aggregated polymer particles of well-defined micron sizes. A crucial difference lies in the volume of the porogen used, this being larger in dispersion polymerization than in rod preparation. 

Attach the flask to a water-cooled reflux condenser, place the assembly in a sand bath, and heat the add solution to 55-60 °C. Now add dropwise, using a calibrated 9-in. Pasteur pipet inserted down the throat of the reflux condenser, 1.0 mL of cydohexanol at a rate of one drop every 30 s. (Gently swirl the reaction mixture in the bath after each addition.)The slow addition is necessary to control the reaction temperature ( ). 

A new strategy for E-caprolactone synthesis is outlined in Scheme 6.9. The aerobic oxidation of cydohexanol (3) catalyzed by N H PI gives a mixture of cyclohexanone (2)... 

Cydohexane is the most important cyclic alkane in industrial organic chemistry and plays a major role in the industrial production of important monomers, such as, for example, adipinic add, adipodinitrile, hexamethylenediamine, hexamethy-lene diisocyanate, and Eproduction processes cyclohexane is oxidized in the first step in a liquid-phase reaction to a mixture of cydohexanol and cyclohexanone. Details about this process are given in Sedion 5.3.3.1. 

Among the industrially produced lactams, e-caprolactam has by far the highest production capacity due to its important role as monomer in the polyamide business. There exist several synthetic routes to produce e-caprolactam. The most important one starts from benzene (Scheme 5.3.7). Benzene is hydrogenated in a first step to cyclohexane, followed by oxidation of the latter to a mixture of cyclohexanone and cydohexanol. This mixture is then reacted with NH2OH to give cyclohexanone oxime, which is converted under add catalysis in a so-called Beckmann rearrangement reaction to e-caprolactam. Alternative routes try to avoid the oxime intermediate (UCC peracetic add process via e-caprolactone), try to avoid the cydohexanone intermediate (e.g., DuPont process converting cydohexane directly into the oxime intermediate by reaction with nitric add), or start from toluene (Snia-Viscosa process). 

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