Cyclohexanol, 2-

Half a porous plate is broken into pieces the size of small peas and the fragments, after being mixed with a solution of 40 g. of chlorine-free nickel nitrate in 20 c.c. of water, are dried, with stirring, on the water bath. The impregnated material is then heated at dull redness in a nickel crucible until evolution of oxides of nitrogen ceases and filled into a combustion tube (leaving at each end 10 cm. empty). 

8 Such fumooes oan easily be constructed from simple materials. See, for example, H. Rupe, Helv. Chim. Acta, 1918, 1, 454 Chem. Fabr., 1929, 50, 519. Cf. also Handbuch der Physik, H. Geiger and K. Soheel, 11, 370 et seq. 

Before the tube is heated it must be completely filled with hydrogen test a sample of the issuing gas by collection in a small test tube and ignition. 

The tube is now heated while a current of hydrogen passes, and the temperature is maintained at 300°-310° until water ceases to appear in the adapter one and half to two hours are required. Then the contents of the tube are allowed to cool in a slow stream of hydrogen. 

After three hours, on the average, the phenol has been completely evaporated and driven over the catalyst. When the receivers have been disconnected the hydrogen current is slowed down and the tube allowed to cool. The contents of the receivers are washed with a little ether into a small dropping funnel and shaken with 10 c.c. of 50 per cent sodium hydroxide solution in order to remove non-hydrogenated phenol. The solution is then decanted from the sodium phenoxide, which is washed with ether and dried with a little 

Amyl alcohols occur in several isomeric forms, most of which are flammable and slightly toxic. These isomers, with their synonyms, CAS number, and some physical properties are presented in Table 4.1. 

Amyl alcohols are used as solvents for resins and gums as diluents for lubricants, printing inks, and lacquers and as frothers in ore flotation process. Amyl xanthates are used as ore collectors in the mining industry. 

Amyl alcohols are colorless liquids with the characteristic odor of alcohol. Neopentyl alcohol is a solid [mp 52°C (125°F)]. Amyl alcohols are slightly soluble in water but mix readily with most organic solvents. Other properties are listed in Table 4.1. 

Inhalation of isoamyl alcohol can cause coughing and irritation of the eyes, nose, and throat. Ingestion may produce narcosis, headache, and dizziness. Cracking of skin may result from the contact. Prolonged contact with isoamyl alcohol can cause dysuria, nausea, and diarrhea. The toxic effects of other isomers in humans are unknown. On the basis of animal studies, it appears that at high concentrations all these isomers could be narcotic and canse eye irritation. 

These are flannnable componnds. The flash point data are presented in Table 4.1. The flammability of 2-methyl-2-bntanol (tert-amyl alcohol) is greater than that of other isomers. The vapors of all isomers form explosive mixtures with air. The LET and UEL values for isoamyl alcohol are 2.4 and 10.5% by volume in air, respectively. Reactions with strong oxidizing substances may be vigorous to violent. 

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Colourless liquid with a strong peppermintlike odour b.p. 155" C. Manufactured by passing cyclohexanol vapour over a heated copper catalyst. Volatile in steam. Oxidized to adipic acid. Used in the manufacture of caprolactam. Nylon, adipic acid, nitrocellulose lacquers, celluloid, artificial leather and printing inks. 

Figure Bl.16.19. (a) CIDEP spectrum observed in die photolysis of xanthone (1.0 x 10 M) in cyclohexanol at room temperature. The stick spectra of the ketyl and cyclohexanol radicals with RPM polarization are presented, (b) CIDEP spectrum after the addition of hydrochloric acid (4.1 vol% HCl 0.50 M) to the solution above. The stick spectra of the ketyl and cyclohexanol radicals with absorptive TM polarization are presented. The bold lines of the stick spectra of the cyclohexanol radical show the broadened lines due to ring motion of the radical. Reprinted from [62].

Alcohols. Methanol, ethanol, n propanol, propan-i-ol.n-butanol, glycol, glycerol, benzyl alcohol, cyclohexanol. 

Physical Properties. All colourless liquids, completely miscible with water, except benzyl alcohol and cyclohexanol, which are slightly soluble. Pure glycol and glycerol have high viscosity, which falls as the hygroscopic liquids absorb water from the air. 

Cyclohexanol gives thenon-volatile adipicacid,HOOC (CH2)4COOH. After heating the mixture under reflux for 10 minutes, cool e flask. 

Cyclohexanone, This is readily oxidised by a KjCr 07 - HjSO mixture to the crystalline adipic acid, m.p. 152 , precisely as for cyclohexanol (p. 335). 

Note 1. The chlorocyclohexane should be free from cyclohexanol, which may lead to inactivation of the magnesium. 

Alkylation of 2-methylaminothiazole (204) with ROH in 85% sulfuric acid gives 2-methylimino-3-alkyl-4-thiazoIine (54). 2-Amino-4-rnethyl-thiazoie alkylated with an excess of isopropanol, however, gives 95% of 2-isopropylamino-4-methyl-5-isopropylthiazole (56). The same result is obtained with cyclohexanol (242). These results and those reported in Sections III.l.C and IV.l.E offer interesting new synthetic possibilities in thiazole chemistry. The reactive species in these alkylations is the conjugate acid of 2-aminothiazole. and the diversity of the products obtained suggests that three nucleophilic centers may be operative in this species. 

Assuming that the rate determining step in the reaction of cyclohexanol with hydrogen bro mide to give cyclohexyl bromide is unimolecular write an equation for this step Use curved arrows to show the flow of electrons... 

Two stereoisomers of 1 bromo 4 methylcyclohexane are formed when trans 4 methyl cyclohexanol reacts with hydrogen bromide Write structural formulas or make molecular mod els of... 

In Problem 5 17 (Section 5 13) we saw that acid catalyzed dehydration of 2 2 dimethyl cyclohexanol afforded 1 2 dimethylcyclohexene To explain this product we must wnte a mecha nism for the reaction in which a methyl shift transforms a secondary carbocation to a tertiary one Another product of the dehydration of 2 2 dimethylcyclohexanol is isopropyhdenecyclopentane Wnte a mechanism to rationalize its formation... 

Let s begin with a simple example Suppose you wanted to prepare cyclohexane given cyclohexanol as the starting material We haven t encountered any reactions so far that permit us to carry out this conversion m a single step... 

Recognizing that cyclohexene may be prepared by dehydration of cyclohexanol a prac tical synthesis of cyclohexane from cyclohexanol becomes apparent... 

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