Cyclododecanols

Nylon-12. Laurolactam [947-04-6] is the usual commercial monomer for nylon-12 [24937-16-4] manufacture. Its production begins with the mixture of cyclododecanol and cyclododecanone which is formed in the production of dodecanedioic acid starting from butadiene. The mixture is then converted quantitatively to cyclododecanone via dehydrogenation of the alcohol at 230—245°C and atmospheric pressure. The conversion to the lactam by the rearrangement of the oxime is similar to that for caprolactam manufacture. There are several other, less widely used commercial routes to laurolactam (171). 

Dodecanedioic Acid. Dodecanedioic acid (DDDA) is produced commercially by Du Pont ia Victoria, Texas, and by Chemische Werke Hbls ia Germany. The starting material is butadiene which is converted to cyclododecatriene usiag a nickel catalyst. Hydrogenation of the triene gives cyclododecane, which is air oxidized to give cyclododecanone and cyclododecanol. Oxidation of this mixture with nitric acid gives dodecanedioic acid (71). 

Nylon 12 first beeame available on a semieommercial scale in 1963. The monomer, dodecanelactam, is prepared from butadiene by a multistaged reaction. In one proeess butadiene is treated with a Ziegler-type eatalyst system to yield the cyclic trimer, cyclododeca-1, 5, 9-triene. This may then be hydrogenated to give cyelododeeane, which is then subjeeted to direct air oxidation to give a mixture of cyclododecanol and cyclododecanone. Treatment of the mixture with... 

Thioanisolc. A system utilizing thio-anisole as an organic mediator was developed for the oxidation of secondary alcohols to ketones (Fig. 5 2-octanol to 2-octanone 99%, menthol to menthone 92%, cyclododecanol to cyclododecanone 75%) [43]. The use of 2,2,2-trifluoroethanol as a solvent in the mediatory system improved the yields [44]. 

Lead hydroxide is used in making porous glass in electrical-insulating paper in electrolytes in sealed nickel-cadmium batteries in recovery of uranium from seawater and as a catalyst for oxidation of cyclododecanol. 

Oxidation of Cyclododecane. 1,12-Cyclododecanedioic acid used in the production of polymers is synthesized in a two-step process864,866 similar to the manufacture of adipic acid. Cyclododecane is first oxidized to a mixture of cyclododecanol and cyclododecanone. Both the cobalt-catalyzed and the borate processes (Huels) are used. Further oxidation of the product mixture leads to 1,12-cyclododecanedioic acid. 

A similar procedure has been developed by Chemische Werke Hulls for the oxidation of cyclododecane to a cyclododecanol-one mixture by air in the presence of boric acid with trace amounts of cobalt(II) carboxylate at 160-180 °C and 1-3 atm.556 The ol-one mixture (5 1) is... 

More reactive hydroperoxides can be converted selectively to alcohols via the method of Bashkirov (Fig. 4.44), where a boric acid ester protects the product from further oxidation and thus increases the selectivity [121]. The method is used to convert C10-C20 paraffins to alcohols which are used as detergents and surfactants, for the oxidation of cyclohexane (see elsewhere) and cyclododecane to cyclododecanol (cyclododecanone) for the manufacture of nylon-12. 

Ti, V and Sn-modified mesoporous silicates were reported to be active in a number of liquid phase oxidation reactions. Ti-containing samples were used for the selective oxidation of large organic molecules in the presence of te/t-butyl hydroperoxide (TBHP) or dilute H2O2 [71,136,137,139-141,147,186,237]. Typical data shown in Table 5 indicate that both Ti-MCM-41 and Ti-HMS are efficient cat ysts for the epoxidation of bulky olefins such as a-terpineol and norbomene in the presence of TBHP or H2O2. Comparison with H-B indicates that the accessibility of active sites plays a critical role in the liquid phase oxidation of organic molecules. Mesoporous titanosilicates also exhibited remarkable activity in the hydroxylation of 2,6-di-rerr-butyl phenol (2,6 DTBP) [142,147] and the oxidation of cyclododecanol [147], naphthol [147] aniline [237] and chloroaniline [186]. However, they were disappointingly poor catalysts for the liquid phase oxidation of n-hexane and aliphatic primary amines, as well as the ammoximation of cyclohexanone [147,238]. 

An even better result is obtained with potassium permanganate in toluene in the presence of neutral alumina. After a mixture of 5 g of alumina, 7.9 g (0.05 mol) of potassium permanganate, and 0.01 mol of cyclododecanol in 50 mL of toluene has been stirred for 30 h at room temperature, a 95% yield of cyclododecanone is obtained [865]. 

A suspension of 15.0 g (4.05 mol) of the reagent in 20 mL of freshly distilled benzene containing 0.250 g (1.36 mmol) of cyclododecanol is heated to 70 °C for 1.5 h. The solution is filtered through Celite (diatomaceous earth), the pellets are washed with 70 mL of benzene, and the combined filtrates are evaporated under reduced pressure to yield 0.226 g (90%) of cyclododecanone as colorless crystals, mp 56-59 °C. The pure compound melts at 59-61 °C. 

Cyclododecanol is dehydrogenated to cydododecanone around 200°C, in the liquid phase, in the presence of a catalyst consisting of copper on alumina. For a 75 per cent conversion, cydododecanol selectivity is 98 molar per cent The reactor effluent is first rid of the hydrogen formed by flash and fractionated in two successive light-ends and heavy-ends separation columns (7 kPa absolute, 25 to 30 trays each). 

C15H30O2, Mr 242.40, is not known in nature. It is a colorless liquid, bpo.i pa 94 °C, df5 0.931, ng° 1.463-1.467, with a noble woody odor with ambergris nuances. It is prepared by reaction of cyclododecanol with paraformaldehyde/hydrochloric gas to give cyclododecyl chloromethyl ether, which is treated with sodium ethylate [116]. 

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