Resorcinol preparation

It occurs in many natural glycosides. It can be prepared by fusing resorcinol with NaOH and is manufactured from trinitrotoluene via trinitrobenzoic acid and triaminobenzene. 

For the preparation of 4-substituted coumarins, a phenol may be condensed with ethyl acetoacetate under the influence of sulphuric acid. Thus resorcinol (II) readily undergoes this condensation (which is represented diagrammatically above) to give 7-hydroxy-4-methyl-coumarin (III). Note that the coumarins, like all 2 pyrones, are systematically lactones. 

Fluorescein is obtained by condensing phthahc anhydride (1 mol) with resorcinol (2 mols) in the presence of anhydrous zinc chloride. The tetra-bromo derivative, readily prepared by the addition of the calculated quantity of bromine, is eosin. 

Uses. Furfuryl alcohol is widely used as a monomer in manufacturing furfuryl alcohol resins, and as a reactive solvent in a variety of synthetic resins and appHcations. Resins derived from furfuryl alcohol are the most important appHcation for furfuryl alcohol in both utihty and volume. The final cross-linked products display outstanding chemical, thermal, and mechanical properties. They are also heat-stable and remarkably resistant to acids, alkaUes, and solvents. Many commercial resins of various compositions and properties have been prepared by polymerization of furfuryl alcohol and other co-reactants such as furfural, formaldehyde, glyoxal, resorcinol, phenoHc compounds and urea. In 1992, domestic furfuryl alcohol consumption was estimated at 47 million pounds (38). 

Another group of halogenated fluorescein dyes is prepared by condensing chloro derivatives of phthalic anhydride with resorcinol, followed by bromination or iodination. Thus Phloxine B /78472-87-2] (Acid Red 92, Cl45410) (42) is prepared by condensing tetrachlorophthaUc anhydride with resorcinol followed by tetrabromination. Phloxine B undergoes ethylation to yield the yellowish ted acid dye Cyanosine B [6441-80-1] (43). 

Dihydroxybenzophenones are used for the syntheses of dyes, polymers, and medicines. They are prepared by the condensation of resorcinol with benzoic acids. Catalysts used for this transformation are sulfonic resins (99), boron trifluoride (100), or zinc chloride in the presence of POCl (101). 

A reexamination of polycarbonate chemistry was carried out about 50 years after the first aromatic polycarbonates of resorcinol and hydroquinone were discovered. In independent investigations at Bayer AG and General Electric, it was discovered that the polycarbonates of BPA could be prepared (eq. 2). Unlike the ahphatic polycarbonates prepared earlier, which were either hquids or low melting sohds, the aromatic polycarbonates were amorphous sohds having elevated glass-transition temperatures. 

It can be prepared by heating resorcinol with an aqueous solution of dimethylamine and its hydrochloride at 200°C under pressure for 12 h (176). The treatment of dimethylaruline with oleum at 55—60°C, followed by fusion with sodium hydroxide at 270—300°C, also gives... 

Pulp Manufacture. Sodium sulfite is utilized in neutral semichemical pulping, acid sulfite pulping, high yield sulfite cooling, and some kraft pulping processes (339). Many pulp mills prepare their own sulfite and recycle as much as possible, but use of merchant sodium sulfite by pulp mills is substantial. Much of the by-product sodium sulfite from resorcinol manufacture goes into pulp appHcations as well as a substantial fraction of the lower assay manufactured sodium sulfite. 

As of 1991 in the United States, OTC antiacne preparations may contain only a few active dmgs, for example, sulfur [7704-34-9] resorcinol acetate [102-29-4], resorcinol [108-46-3], salicylic acid [69-72-7], and some combinations (52). OTC anti-acne constituents maybe included in a variety of conventional cosmetic preparations, which then become OTC dmgs. These include lotions, creams, solutions, facial makeups, facial cleansers (including abrasive cleansers), and astringents. Products must contain the specified dmgs at the designated concentrations. Compositions of antiacne products have beenpubhshed (53). 

HPLC method with amperometric detection was applied for detenuination of phenols in sea sediment and some dmg preparation. Peaks of phenol, guaiacol, cresols, hydroquinon and resorcinol were identified on chromatogram of birch tai. The HPLC method with electrochemical detectors was used for detenuination of some drug prepai ation of aminophenol derivate. So p-acetaminophenol (paracetamol) was determined in some drug. 

Bromoresorcinol has been prepared by the monobromination of resorcinol monobenzoate and subsequent hydrolysis, from 2-bromo-5-aminophenol by the diazo reaction, by treating resorcinol with dichlorourea and potassium bromide, and by the bromination of 2,4-dihydroxy benzoic acid followed by decarboxylation. The above procedure is based particularly upon the observations of Rice. ... 

Polycarbonates were first prepared by Einhom in 1898 by reacting the dihydroxybenzenes, hydroquinone and resorcinol, separately with phosgene in solution in pyridine. The hydroquinone polycarbonate was an infusible and insoluble crystalline power whereas the resorcinol polymer was an amorphous material melting at about 200°C. The third dihydroxybenzene, catechol, yields a cyclic carbonate only, which is not surprising bearing in mind the proximity of... 

In the manufacture of pure resorcinol resins, the reaction can be violently exothermic unless controlled by the addition of alcohols. Because the alcohols perform other useful functions in the glue mix, they are left in the liquid adhesive. PRF adhesives are generally prepared firstly by reaction of phenol with formaldehyde to form a PF resol polymer, that has been proved to be in the greatest percentage, and often completely, linear [95], In the reaction step that follows the resorcinol chemical is added in excess to the PF-resol to react it with the PF-resin -CH2OH groups to form PRF polymers in which the resorcinol groups can be resorcinol chemical or any type of resorcinol-formaldehyde polymer. 

Where resorcinol adhesives are not suitable, resins can be prepared from modified resorcinol [128], Characteristic of these types of resins arc those used for tyre cord adhesives, in which a pure resorcinol-formaldehyde resin is used, or alternatively, alkyl resorcinol or oil-soluble resins suitable for rubber compounding are obtained by prereaction of resorcinol with fatty acids in the presence of sulfuric acid at high temperature followed by reaction with formaldehyde. Worldwide more than 90% of resorcinol adhesives are used as cold-setting wood adhesives. The other most notable application is as tyre cord adhesives, which constitutes less than 5% of the total use. 

Fluororesorcinol can be prepared from derivatives of resorcinol and fluo-roxytrifluoromethane [15, 24] (equation 4) or by fluorination of resorcinol with cesium fluoroxysulfate [25] (equation 5). Reaction of acetyl hypofluorite with M-acetyl-O-methyltyrosine methyl ester provides a good route to 3-fluorotyrosine derivatives [26] (equation 6). 

Hydrogenolysis of methylenediisoxazoles have been useful in preparing substituted resorcinols and aminophenols (7). The isoxazole annelation reaction (71,89,90,91,103) is well suited to the synthesis of steroids and other complex molecules. 

Al Preparation of 7-Hydroxy-4,8-Dimethy/coumarin Chilled ethyl acetoacetate (157 ml, 1.20 mols) followed by 2-methyl-resorcinol (130 g, 1.04 mols) was dissolved in well-stirred concentrated sulfuric acid (600 ml) at such a rate as to keep the temperature below 10°C (ice bath). The stirred solution was allowed to warm gradually and after 3 hours was added to water (ca 8 liters) with mechanical stirring. The product was collected, washed twice with water, and dried at 70° to 80°C until the first sign of darkening. Yield 191.3 g (95.4%). Recrystallization from aqueous ethanol gave 7-hydroxy-4,8-dimethylcoumarin as colorless needles, MP 260.5° to 261°C. In dilute sodium hydroxide, the compound gives a yellow solution which exhibits blue fluorescence. 

The azolotriazines 294 were prepared (86KGS1137) by heating resorcinol with the corresponding nitroazole 293 in butanol. The pKa values of some nitropyrazolotriazinones have been calculated (84KGS697). Az-... 

Tkble 3.1. Preparation of Jessner s Solution with resorcinol... 

Place iodine crystal in a closed tank place the plates in the tank nntil color appears Prepare a 2% aqneons solntion of resorcinol add 10 ml of this solntion to 80 ml of HCl containing 10.5 ml of 0. l-MCnS04 solntion spray the plates with the reagent and heat for few min at 110°C... 

A hydrogenation process for the preparation of 4,6-diamino resorcinol from 4,6-bisphenylazo resorcinol was studied and developed up to pilot scale. The high reaction rate together with the protection of the product against oxidation could ensure providing the addition of HCl was made after the fast hydrogenation period. Activity and lifetime of commercial catalysts were evaluated also. 

While these agents may cause less skin irritation than benzoyl peroxide or the topical retinoids, several disadvantages exist. Sulfur preparations produce an unpleasant odor when applied to the skin, while resorcinol may cause brown scaling. And although rare, the possibility of salicylism exists with continual salicylic acid use.3,12... 

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