Salicylic alcohol

C7H6O2 Oily liquid of aromatic odour b.p. 196°C. (t is prepared by the action of chloroform and caustic potash on phenol (the Reimer-Tiemann reaction) or by the oxidation of the glucoside salicin. It is easily reduced to salicyl alcohol or oxidized to salicylic acid. 

CgHiiOg-OCgHgCHgOH + H,0 - C,H 0, -I- HOC,H CH,OH salicin glucose salicyl alcohol... 

Salicin is a colourless crystalline substance, soluble in water. It does not reduce Fehling s solution nor does it give a coloration with ferric chloride. On hydrolysis with emulsin, glucose and salicyl alcohol are produced the former reduces Fehling s solution and the latter gives a violet coloration with ferric chloride. 

Cool the remainder of the filtrate and extract three times with ether, using 20 - 30 ml. for each extraction. Dry the combined ethereal extracts over powdered anhydrous sodium sulphate. Filter into a small flask and distil off the ether on a water-bath. Pour the residual oil into a small dish or beaker crystallisation takes place almost immediately. The salicyl alcohol so obtained is almost pure, but it may, if so desired, be recrystallised from a small quantity of benzene. It is a colourless crystalline solid, m.p. 86 , readily soluble in water it gives a violet coloration with ferric chloride. 

Salicyl alcohol was purchased from Lancaster, UK or from Fluka and used as received. 

Saccharin 10,11,174, 388-390 Salicyl alcohol 195 Salicylaldehyde reagent 284 Salicylic acid 45,171, 175,178, 233, 308 Salicylsalicin 195,196 SalitUon 151... 

This chapter compares the reaction of gas-phase methylation of phenol with methanol in basic and in acid catalysis, with the aim of investigating how the transformations occurring on methanol affect the catalytic performance and the reaction mechanism. It is proposed that with the basic catalyst, Mg/Fe/0, the tme alkylating agent is formaldehyde, obtained by dehydrogenation of methanol. Formaldehyde reacts with phenol to yield salicyl alcohol, which rapidly dehydrogenates to salicyladehyde. The latter was isolated in tests made by feeding directly a formalin/phenol aqueous solution. Salicylaldehyde then transforms to o-cresol, the main product of the basic-catalyzed methylation of phenol, likely by means of an intramolecular H-transfer with formaldehyde. With an acid catalyst, H-mordenite, the main products were anisole and cresols moreover, methanol was transformed to alkylaromatics. 

Jones, R. M. Selenski, C. Pettus, T. R. R. Rapid syntheses of benzopyrans from o-OBOC salicylaldehydes and salicyl alcohols a three-component reaction. J. Org. Chem. 2002,67, 6911-6915. 

Salicylic alcohol glucosides, natural, 22 7 Salicyloyl chloride, 22 3 Salicylsalicylic acid, 22 16-17 physical properties of, 22 15t Saligenin, 22 23, 24 Salina salt, 5 788 Saline hydrides, 13 771 Saline solutions... 

Take aspirin, for example. It has its origins in salicin, the active ingredient in willow bark. When salicin is hydrolysed it produces glucose and salicyl alcohol the latter can be oxidised to salicylic acid. Salicylic acid was also used as a medicine, but it caused irritation and bleeding in the stomach and intestines. However, when salicylic acid is treated with ethanoic anhydride, acetylsalicylic acid (aspirin) is produced. 

Salicin is an (9-glycoside of a phenol, namely salicyl alcohol. Salicin is a natural antipyretic and analgesic found in willow bark, and is the template from which aspirin (acetylsalicylic acid, see Box 7.13) was developed. Prunasin from cherry laurel is an example of a cyanogenic glycoside, hydrolysis of which leads to release of toxic HCN (see Box 7.7). It is the (9-glucoside of the alcohol mandelonitrile, the trivial name for the cyanohydrin of benzaldehyde. It is the further hydrolysis of mandelonitrile that liberates HCN. 

The bromide leaving group is now nicely positioned for an Sn2 reaction with an incoming nucleophile in the example shown, this is the phenoxide anion from salicyl alcohol. In the presence of base, the phenolic group of salicyl alcohol is ionized, since phenols are very much more acidic than alcohols (see Section 4.3.5). Sn2 processes occur with inversion of configuration (see Section 6.1), so... 

Nucleophilic ring opening of salicyl alcohol acetals was effected by borane-trimethylamine upon Lewis acid activation with AICI3. This reaction was particularly useful for the construction of fluorescently labeled compounds (Equation 29) <2006JOC3444>. 

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