Salicyl alcohol, preparation

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. 

Numerous methods for the synthesis of salicyl alcohol exist. These involve the reduction of salicylaldehyde or of salicylic acid and its derivatives. The alcohol can be prepared in almost theoretical yield by the reduction of salicylaldehyde with sodium amalgam, sodium borohydride, or lithium aluminum hydride by catalytic hydrogenation over platinum black or Raney nickel or by hydrogenation over platinum and ferrous chloride in alcohol. The electrolytic reduction of salicylaldehyde in sodium bicarbonate solution at a mercury cathode with carbon dioxide passed into the mixture also yields saligenin. It is formed by the electrolytic reduction at lead electrodes of salicylic acids in aqueous alcoholic solution or sodium salicylate in the presence of boric acid and sodium sulfate. Salicylamide in aqueous alcohol solution acidified with acetic acid is reduced to salicyl alcohol by sodium amalgam in 63% yield. Salicyl alcohol forms along with -hydroxybenzyl alcohol by the action of formaldehyde on phenol in the presence of sodium hydroxide or calcium oxide. High yields of salicyl alcohol from phenol and formaldehyde in the presence of a molar equivalent of ether additives have been reported (60). Phenyl metaborate prepared from phenol and boric acid yields salicyl alcohol after treatment with formaldehyde and hydrolysis (61). 

Au/Fe2 03 catalysts prepared by CP [382] and Au catalysts prepared by IMP on Fe203, ZnO, CaO and AI2O3 [383] have been shown to catalyse the oxidation of o-hydroxybenzyl alcohol (salicylic alcohol) under mild conditions. Salicylic aldehyde is the main reaction product with a selectivity >90% at 90% conversion [383]. Sodium carbonate treatment of the catalyst probably removed most of the chloride which would otherwise be a poison. 

Alkylsilyl cyanides such as Et2Si(CN)2 can be used to silylate dihydroxy compounds such as salicyl alcohol or salicylic acid to obtain 4//-l,3,2-benzodioxasilins (e.g. E = 0 in Equation (5) <86JOC3545 . They can also be prepared regio- and stereoselectively in intramolecular Diels-Alder reactions of R 2Si(OR )(OR ) species (R = Ph or Bu , R = butadienyl, R = substituted vinyl) <91TL1145>. 

Improved yields in the Ullmann reaction could be realized using activated copper powder obtained by in situ reduction of Cu(I) iodide with potassium [21]. Unsymmetrical 2,2 -biphenyls were prepared using a salicylic alcohol template combined with the catalytic effect of activated copper [22]. 

Scheme 10-119 Salicyl alcohol is a useful template for the preparation of unsymmetrical biaryls.

D-Glucose orthoesters of complex alcohols can be easily obtained with the help of silver salicylate Alcohols and amines can be conveniently prepared from olefins by ozonization-reduction and ozoni-zation-reductive amination respectively without isolation of intermediates Inverted amines can be obtained from optically-active alcohols through stereospecific formation of N-alkylphthalimides 3-Methoxy-l-phenyl-l-propyne has been used as starting material for the synthesis of a,/ -unsatd. carbonyl compounds through allenic di-carbanions a-Ketocarboxylic acids can be easily prepared from cyanohydrins through a Ritter reaction... 

Since their discovery, many model compounds of the ortho-ortho novolac type have been synthesized. Thus, Casiraghi and coworkers here prepared a series of dinuclear to nonanuclear dA -ortho methylene-bridged oligophenols by a repetitive reaction sequence involving the C-ortho regiospecific condensation of the appropriate phenoxymagnesium precursors with salicyl alcohol or paraformaldehyde. Previous methods invariably started from phenolic synthons, with suitable protection to avoid side reactions at the other free sites of the substrate, but the newer method circumvents the need for protection. 

A method of preparation is to react an acid salt of choline (such as choline chloride or choline bromide) with an alkaline salt of salicylic acid (such as sodium salicylate, potassium salicylate, or magnesium salicylate) in an alcoholic media. 

Conversion of Acid Anhydrides into Esters Acetic anhydride is often used to prepare acetate esters from alcohols. For example, aspirin (acetylsalicylic acid) is prepared commercially by the acetylation of o-hydroxybenzoic acid (salicylic acid) with acetic anhydride. 

Aspirin Salicylic Acid Dissolve 2.5 g in 25 ml alcohol (TS). To each of two matched cylinders add 48 ml of water and 1 ml of freshly prepared Ferric Ammonium Sulph. Reagent1. Into one cylinder pippete 1 ml of stand, salicylic acid soln. (0.01 % w/v in water) and into the other pipette 1 ml of TS. Mix the contents of the cylinder, after 30 secs, the colour of the second cylinder is not more intense than the first cylinder. NMT 0.1... 

The a- and /3-cyclodextrins have been found to accelerate the Smiles rearrangement of 4-nitrophenyl salicylate. The reaction of 2,4-dinitrobenzenesulfonamide with acyl chlorides in the presence of excess triethylamine has been found to produce the corresponding nitrile in good yield. Mechanistic studies have indicated that the reaction proceeds via a Smiles rearrangement of the initially formed iV-(2,4-dinitrobenzenesulfonyl)amide to form the nitrile, 2,4-dinitrophenol, and sulfur dioxide (see Scheme 12). l-Chloro-3-fluorophenothiazines have been prepared by Smiles rearrangement of 3-chloro-5-fluoro-2-formamido-2 -nitrophenyl sulfides in alcoholic... 

The complexes [Ru(bpy)2L]+ (HL = acetylacetone, trifluoroacetylacetone, hexafluoroacetylace-tone, tropolone or dibenzoylmethane) have been prepared and characterized they act as catalysts for the oxidation of alcohols, 3,5-di-tert-butylcatechol and alkanes in the presence of appropriate co-oxidants." Perchlorate salts of [Os(bpy)2L] in which HL = salicylaldehyde, 2-hydroxyaceto-phenone or 2-hydroxynaphthaldehyde, are formed from reactions of [Os(bpy)2Br2] with HL. The structure of the salicylaldehyde derivative has been determined. Chemical and electrochemical oxidations of [Os(bpy)2L]" yield the corresponding low-spin Os species from which [Os(bpy)2L]+ can be regenerated." " [Ru(bpy)2L]" (HL = salicylic acid) has been prepared and structurally characterized as the tetrahydrate. Absorptions at 590 nm, 400 nm, and 290 nm in the electronic spectrum have been assigned to Ru bpy CT transitions electrochemical oxidations of the complex have been investigated." ... 

Hydroxybenzoic acid is obtained as white crystals, fine needles, or fluffy white crystalline powder. It is stable in air and may discolor gradually in sunlight. The synthetic form is white and odorless. When prepared from natural methyl salicylate, it may have a light yellow or pink tint and a faint, wintergreen-like odor. w-Hydroxybenzoic acid crystallizes from water in the form of white needles and from alcohol as platelets or rhombic prisms. -Hydroxybenzoic acid crystallizes in the form of monoclinic prisms. Various physical properties of hydroxybenzoic acids are listed in Tables 1—4. 

Benzyl salicylate can be prepared by the reaction of benzyl chloride with an alkali salt of salicylic acid at 130—140°C or by the transesterification of methyl salicylate with benzyl alcohol. It is used as a fixative and solvent for nitro musks and as a fragrance for deteigents. Benzyl salicylate was priced at... 

Sahcylsalicylic acid [532-94-3] (salsalate) is prepared by the action of phosphoms trichloride, phosphoms oxychloride, or thionyl chloride on salicylic acid at low temperatures in an appropriate solvent. The cmde product is recrystallized rapidly from ethyl alcohol to avoid hydrolysis and esterification. It is used as an analgesic and an antipyretic, as well as in the treatment of acute and chronic rheumatism and arthritis. It does not induce gastric disturbances because it is only slowly hydrolyzed in the intestine. Owing to the slowness of its hydrolysis (two molecules of salicylic acid per molecule of the ester), the action of sahcylsalicylic acid is less prompt but more persistent than that of other salicylates. Other salicylates of interest include ethylene glycol mono salicylate [87-28-5], dipropylene glycol monomethylether salicylate, bomyl salicylate [560-88-3], and -acetamidophenyl salicylate [118-57-0]. 

Some researchers noticed that some chemicals attract adult of Amblyomma [107,108]. Among these substances many were of natural origin, such as nonanoic acid, methyl salicylate, benzyl alcohol, benzaldehyde, heptadecane and squalene. Other authors exploited this feature to prepare some drugs in which the acaricides were associated to the pheromone-like chemicals to control Amblyomma [109,110]. 

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