Kekule oil

Kekule Oil. A liq expl (d=l ATglee) prepd in 1869 by passing ethylene gas into mixed nitric-sulfuric acid. The oil consisted of a mixt (about 50/50) of Nitroglycol, CH2(0N02)-CH2(0N02), and beta-Nitroethyl Nitrate, CH2(0N02)CH2N02... 

On distilling Kekule oil in steam and in vacuum were obtd Nitroglycol, bp 105° at 19mm and / -Nitroethyl Nitrate, bp 120—122° at 17mm... 

The crude Kekule oil, when freed from admixed and dissolved acid by washing with water, contd 40—50% 2-Nitroethanol Nitrate and 50—40% Nitroglycol. On shaking the oil with very dil caustic alkali, the Nitroethanol Nitrate is removed leaving pure Nitroglycol. Numerous patents have been issued for processes of procuring pure Nitroglycol from Kekule oil (Refs 4 5)... 

A. Kekule prepd in 1869 an unstable liquid (known now as Kekule Oil) when he passed ethylene thru a cooled nitric-sulfuric acid mixture, which he designated as ethyleneglycol nitrate-nitrite. Later, Wieland Sakeilarios (Ref 2) showed that this product was a mixt of ethyleneglycol dinitrate and and the nitric acid ester of 2-NitroethyI Alcohol (See also Ref 4)... 

This 2nd reaction, in which a 3rd mole of nitric acid drives out the nitrous acid, explains the rather high content of nitrogen oxides in the spent acid. This mixture of 40—50% Nitroethyl Nitrate 40—50% Nitro-glycol is known as Kekule Oil . As its N content is up to 19 5% which is even higher... 

A simple method of separating NGc from Kekule Oil was described in GerP 384107 of 1923. Here the oil was slowly distilled with steam or better digested with w at 80—90°, until the Nitroethyl Nitrate it contained was almost completely converted into products sol in w. 

A considerable amount of nitrous acid is present in the spent acid. /J-Nitroethyl nitrate is feebly acidic and dissolves in dilute alkali solutions with a yellow color. It is not sufficiently stable for use in commercial explosives. On digestion with warm water or on slow distillation with steam it undergoes a decomposition or sort of hydrolysis whereby nitrous acid and other materials are produced. Numerous patents have been issued for processes of procuring pure nitroglycol from the Kekule oil. One hundred parts of the last-named material yield about 40 parts of nitroglycol, and the economic success of the Process depends upon the recovery of valuable by-products from the 0-nitroethyl nitrate which is destroyed. ... 

OB to C02 —11.7% very volatile, toxic liquid with irritating odor sp gr 1.468 at 18°, mp — not given, bp 120—122° at 17mm and 103° at 15mm decomp at 185° with evoln of brown fumes and chars at 260° sol in w distills with vapors of w ale being si acidic, it dissolves in cold caustic alkali solns, giving a yellow color. It was first prepd in 1920 by Wieland Sakellarios (Refs 1 3) from the same kind of oil as was obtd by Kekule in 1869 (Refs 1 2) on passing ethylene into a mixture of coned nitric and sulfuric acid. 

WALLACH, OTTO (1847-1931). German chemist who received the Nobel prize for chemistry in 1910 for recognition of his services to organic chemistry and the chemical industry by his pioneer work tn the field of alic.yclic compounds. His mentors were Hofmann and Wahler, and he worked at the University of Bonn under Kekule. He studied pharmacy and did work on terpenes. camphors, and essential oils. This was followed by research in aromatic oils, perfumes, and spices. His research of terpenes revealed their significance in sex hormones and vitamins. Ethereal oils and industrial uses were made possible by his work. 

Benzene, first obtained from compressed oil gas in 1825 by Faraday, was an interesting enigma. With a formula of C H, it was highly unsaturated and would have been expected to undergo addition reactions like ethylene and other olefins. Its chemistry was remarkably different from that expected. Once again Kekule claims to have dreamed up a solution ... 

The eighth Nobel Prize was awarded to Ernest Rutherford for his work on the composition of the atom. While today this work might be considered more in the realm of physics, this award for chemistry emphasizes the overlap of the two fields. Chemistry could not progress without physics, but we dare say physics would not progress without chemists. Wilhelm Ostwald received the ninth Nobel Prize for his work in the field of physical chemistry, as this study of the border area between physics and chemistry came to be known. Otto Wallach, another product of Kekule s laboratories, received the tenth Nobel Prize for his work in organic chemistry, mostly on elucidating structures of plant oils, terpenes. The eleventh prize went to Marie Curie for her chemical work on polonium and radium. She had already shared the 1903 Nobel Prize in physics with her husband and Henri Becquerel... 

Otto Wallach (Konigsberg, 27 March 1847-Gottingen, 22 (or 26) February 1931) studied under Wohler and Hiibner in Gottingen (1867), was assistant to Wichelhaus in Berlin (1868) and Kekule in Bonn (1870), where he became associate professor (1876), also teaching pharmacy and so becoming interested in ethereal oils. He succeeded Victor Meyer in Gottingen in 1889, retiring in 1915. He was essentially an experimenter. He received the Nobel Prize in 1910. ... 

At that time, hydrocarbons occurring in essential oils with the molecular formula C,oH g were known, which had been named by Kekule terpenes because of their occurrence in turpentine oil. Constituents with the molecular formulas CigHigO and C,oH,gO were also known at that time under the generic name camphor and were obviously related to terpenes. The prototype of this group was camphor itself, which was known since antiquity. In 1891, Wallach characterized the terpenes pinene, camphene, limonene, dipentene, phellandrene, terpinolene, fenchene, and sylvestrene, which has later been recognized to be an artifact. 

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