Creosol

Medicinal creosote is a mixture of phenols, chiefly guaiacol and creosol (4-melhyl-2-meth-oxyphenol), obtained by distillation of wood tar. B.p. 480-500 K. It is almost colourless with a characteristic odour and is a strong antiseptic, less toxic than phenol. 

The benzene is removed under reduced pressure by distillation on a steam bath. The residue is distilled under reduced pressure, the fraction boiling at 78-79°/4 mm., at 104-105°/15 mm., or at 219-222.5°/760 mm. being collected. A yield of 83-92.5 g. (60-67%) of colorless or pale yellow creosol is obtained, df, 1.092 ... 

The reduction of vanillin by the Clemmensen method using toluene as an auxiliary solvent has been reported.3 By following these directions, a yield of 49% of creosol was obtained with large amounts of tar. 

Creosol (also called 2-methoxy-jb-cresol, 4-methylguaiacol, and 3-methoxy-4-hydroxytoluene) has been obtained by the fractionation of beach creosote tar,4 by the reduction of vanillin by electrolytic methods,6 6 by hydrogen and palladium on charcoal or barium sulfate,7 8 with hydrazine,9 and by amalgamated zinc and hydrochloric acid.3 10 11 It has also been prepared by methyl-ation of 4-methylcatechol with methyl iodide 12 13 or with methyl sulfate 14 and is reported to be formed by the distillation of the calcium salt of 3-methoxy-4-hydroxyphenylacetic acid.16... 

Creosol, 33, 17 Crotonaldehyde, 33, IS 34, 29 diethyl acetal, 32, 5 Cupric acetate monohydrate, 36, 77 Cuprous oxide-silver oxide, 36, 36, 37 Cyanamide, 34, 67 36, 8 Cyanoacetamide, 32, 34 Cyanoacetic acid, 31, 25 Cyanoacetylurea, 37, 16 >-Cyanobenzaldehyde, 30, 100 >-Cyanobenzaldiacetate, 36, 59 3-Cyano-5,6-dimethyl-2(l)-pyridone, 32,34 N-2-Cyanoethylaniline, 36, 6 N-2-Cyanoethyl- -anisidine, 36, 7 Cyanoethylation, of aniline, 36, 6 of ethyl phenylcyanoacetate, 30, 80 N-2-Cyanoethyl-m-chloroaniline, 36, 7 Cyanogen, 32, 31 Cyanogen iodide, 32, 29 Cyanogen iodide, complex with sodium iodide, 32, 31... 

Gierer, J., Yang, E. and Reitberger, T. (1992). The reactions of hydroxyl radicals with aromatic rings in lignins, studied with creosol and 4-methylveratrol. Holzforschung, 46(6), 495-504. 

The odor of cresol is recognized at concentrations as low as 5ppm. The 2003 ACGIH threshold limit value-time-weighted average (TLV-TWA) for all isomers of creosol is 5 ppm (22mg/m ) with a notation for skin absorption. 

SafeSoil has been used primarily on soils contaminated with petroleum products, since these contaminants are most susceptible to biological treatment. Full-scale studies indicate that the SafeSoil technology successfully treats soil contaminated with solvents, gasoline, waste oil, jet fuel (JP-4), kerosene, diesel fuel, creosols, and phenols. 

Scheme 22.7 Production of vanillin from creosol by two enzymatic reactions [83]...

The second pathway using VAO reported by van den Heuvel et al. [83] is the VAO-catalysed oxidation of vanillyl alcohol to vanillin. Vanillyl alcohol is not very abundant in nature but can be generated by VAO-catalysed conversion of creosol (2-methoxy-p-cresol). As creosol can be found in creosote obtained from heating wood or coal tar, the feedstock for this pathway is very abundant. 

The process comprises two steps the conversion of creosol to vanillyl alcohol and the oxidation of the alcohol to vanillin (Scheme 22.7). Interestingly, these two steps are catalysed by the same enzyme, i.e.VAO. 

N.A. Pimpinella anisum L. Anethole, creosol, coumarin, acetylinic, flavonoids, fatty oil, protein." Antispasmodic, carminative, diuretic, relieve gas pain. 

Coupling, of diazotized Ji-aminoaceto-phenone with quinone, 34, 1 of diazotized 3,5-dichloro-2-aminoben-zoic acid to give 4,4, 6,6 -tetra-chlorodiphenic acid, 31, 96 of dibromomalononitrile to tetracyanoethylene, 39, 65 of diphenyldichloromethane to tetra-phenylethylene, 31,104 Creased flask, 37, 55 Creosol, 33,17 Crotonaldehyde, 33, 15 34, 29 diethyl acetal, 32, 5 reaction with ethynylmagnesium bromide, 39, 57... 

Creosol (2-methoxy-4-methylphenol) (I), for instance, yields 14.5% methanol and 15% carbon dioxide on a mole basis. Besides these degradation products, up to 60% of the crystalline o,o -dihydroxybiphenyl derivative (6,6 -bicreosol—i.e., 2,2 -dihydroxy-3,3 -dimethoxy-5,5 -dimethylbi-phenyl-1,1 ) (II) and small amounts of a higher molecular humic-like compound could be isolated. 

Figure 3. Electron spin resonance spectra of the high molecular fraction of creosol oxidation product...

Figure 4. Formation of resonance-stabilized free phenoxyl radicals of creosol (I) by oxidation in aqueous alkali...

However, our discussion will be restricted to oxidation of simple alkylated monohydric phenols (2-methoxy-4-alkylphenols), serving as models for noncondensed lignin units. In creosol (I) one ortho position and the para position is blocked, and coupling occurs at the 0-carbon atom under the conditions used. Other coupling mechanisms could not be detected (Figure 7). 

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