Gum benzoin

It was first described in 1608 when it was sublimed out of gum benzoin. It also occurs in many other natural resins. Benzoic acid is manufactured by the air oxidation of toluene in the liquid phase at 150°C and 4-6 atm. in the presence of a cobalt catalyst by the partial decarboxylation of phthalic anhydride in either the liquid or vapour phase in the presence of water by the hydrolysis of benzotrichloride (from the chlorination of toluene) in the presence of zinc chloride at 100°C. 

Benzoic acid had been known for several hundred years by the time of Mitscher lich s experiment Many trees exude resinous materials called balsams when cuts are made m their bark Some of these balsams are very fragrant which once made them highly prized articles of commerce especially when the trees that produced them could be found only m exotic faraway lands Gum benzoin is a balsam obtained from a tree that grows m Java and Sumatra Benzoin is a word derived from the Erench equivalent benjoin which in turn comes from the Arabic luban jawi meaning incense from Java Benzoic acid is itself odorless but can easily be isolated from gum benzoin... 

Benzoic acid [65-85-0] C H COOH, the simplest member of the aromatic carboxyHc acid family, was first described in 1618 by a French physician, but it was not until 1832 that its stmcture was deterrnined by Wn b1er and Liebig. In the nineteenth century benzoic acid was used extensively as a medicinal substance and was prepared from gum benzoin. Benzoic acid was first produced synthetically by the hydrolysis of benzotrichloride. Various other processes such as the nitric acid oxidation of toluene were used until the 1930s when the decarboxylation of phthaUc acid became the dominant commercial process. During World War II in Germany the batchwise Hquid-phase air oxidation of toluene became an important process. 

Benzoic acid in the free state, or in the form of simple derivatives such as salts, esters, and amides, is widely distributed in nature. Gum benzoin (from styrax ben in) may contain as much as 20% benzoic acid in the free state or in combinations easily broken up by heating. Acaroid resin (from anthorrhoca haslilis) contains from 4.5 to 7%. Smaller amounts of the free acid are found in natural products including the scent glands of the beaver, the bark of the black cherry tree, cranberries, pmnes, ripe cloves, and oil of anise seed. Pern and Tolu balsams contain benzyl benzoate the latter contains free benzoic acid as well. The urine of herbivorous animals contains a small proportion of the glycine derivative of benzoic acid, hippuric acid [495-69-2] (CgH CONHCH2COOH). So-called natural benzoic acid is not known to be available as an item of commerce. 

The following materials may be ground at ordinary temperatures if only the regular commerci fineness is required amber, arabac, tragacanth, rosin, olibanum, gum benzoin, myrrh, guaiacum, and montau wax. If a finer product is required, hammer mills or attrition mills in closed circuit, with screens or air classifiers, are used. 

A.S., abbrev. (Amp re-Stunde) ampere-hour, Aaant, Asand, m. — stinkender —, asafetida. — wohlriechender —. gum benzoin. 

I. Pastorova, C.G. de Koster, J.J. Boon, Analytical study of free and ester bound benzoic and cinnamic acids of gum benzoin resins by GC MS and HPLC frit FAB MS, Phytochemical... 

Kermack and Wright Biochem. J. XVII. 635,1923) have shown that gelatine at a of 4 T exerts but little protective power on a negative gum benzoin sol, acid gelatine precipitates the colloid in small concentrations whilst alkaline gelatine protects it. Similar observations have been made by Zsigmondy on the effect of casein on gold, but its exact isoelectric point was not established. 

Brom gum benzoin, by eublunation, or by extraction with potassic hydrate and aubsequmt precipitation of the acid by hydrocUorie acid. 

Benzoic acid occurs naturally in some fruits and vegetables, notably in cranberries, where it occurs in amounts of the order of 0.08% m/m (Fellows Esselen, 1955). It is also found in some resins, chiefly in gum benzoin (from Styrax ben-zoia), and in coal tar. Commercially available benzoic acid is produced by chemical synthesis. 

Although benzoic acid occurs naturally in some substances, such as gum benzoin, dragon s blood resin, balsams, cranberries, and the urine of the ox and horse, the product is made on a large scale by synthesis from other materials. Benzoic acid can be manufactured by the liquid-phase oxidation of toluene by air in a continuous oxidation reactor operated at moderate pressure and temperature ... 

The name benzene was disputed in the 19th century. V. Meyer proposed "benzene from benzoin because the means of preparing pure benzene involved decarboxylation of benzoic acid using sodium hydroxide at high temperature (otherwise, thiophene was an impurity that proved difficult to remove). Benzoic acid was obtained from gum benzoin as a white powder. On the other hand, Auguste Laurent, who inter alia taught crystallography to Louis... 

To Hake Hatches Without Sulphur. To obviate the use of sulphur for igniting tho wood of the match, the ends of the matches aro first slightly charred by rubbing them against a red hot iron plate, and then dipped into as much white wax, melted in a suitable vessel, as will cover the bottom about i inch in depth. Or they may be dipped into camphorated spirit. Or into a solution of 1 ounce Venice turpentine and k ounce camphor, in pint oil of turpentine, with a little gum-benzoin and eascarilla by way of perfume. After any of the above preparations the matches are ready for dipping in the phosphorus paste. 

Occurrence.—Benzoic acid is a naturally occurring substance being found both free and as esters in gum benzoin Peru and Tolu balsams huckleberries, the flower, dragon s blood, etc. It also occurs in combina-... 

Protocatechuic Acid.—One of the di-hydroxy benzoic acids is related to vanillin, which we have already studied. The acid is known as protocatechuic acid, and derives its name from the fact that it may be obtained from a gum or resin, known as gum catechin by fusion with potash, i.e. by heat and oxidation in presence of an alkali. A large variety of plant products including alkaloids essential oils, gums, resins and tannins yield this acid. The following may be mentioned gum catechin, gum benzoin, guaiac resin, myrrh, piperine or piperic acid, vanillin, cafe-tannic acid. These natural sources at once suggest a relationship to vanillin (p. 661) and heliotropin (p. 662). It is the acid corresponding to protocatechuic aldehyde, 3-4-di-hydroxy benzal-dehyde (p. 661), which explains the relationship just mentioned. Its constitution, is then ... 

Benzyl Alcohol, NF. Ben/yl alcohol (phenylcarbinol. phenylmethanol) occurs naturally as the unesteriried form in oil of jasmine and in esters of acetic, cinnamic, and benzoic acids in gum benzoin,. storax re.sin. Peru balsam, tolu balsam, and some volatile oils. It is. soluble in water and alcohol and is a clear liquid with an aromatic odor. 

Benzoic Add, USP. Benzoic acid and its esters occur naturally in gum benzoin and in Peru and tolu balsam.s. It is found as a white crystalline solid that slowly sublimes at room temperature and is steam distillable. It is slightly soluble in water (0.3%) but more. soluble in alcohol and in other polar organic. solvents. It has a pK of 4.2. Benzoic acid is used externally as an antiseptic in lotions, ointment.s. and mouthwashes. It is mure effective as a preservative in foods and pharmaceutical products at low pH (Ic.ss than the pK ). When used as a preservative in emulsions, its effectiveness depends on both pH and distribution into the two pha.scs. ... 

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