74-90-8 hydrocyanic acid

GattermaDD synthesis A method for the synthesis of aromatic hydroxyaldehydes. E.g. AICI3 is used to bring about the condensation of phenol with a mixture of gaseous hydrochloric acid and hydrocyanic acid an aldimine hydrochloride is formed and on hydrolysis gives p-hydroxybenzaldehyde... 

The maximum permissible body burden for ingested polonium is only 0.03 microcuries, which represents a particle weighing only 6.8 x IO-12 g. Weight for weight it is about 2.5 x lOii times as toxic as hydrocyanic acid. The maximum allowable concentration for soluble polonium compounds in air is about 2 x lO-ii microcuries/cnu. 

Miscellaneous Reactions. Sodium bisulfite adds to acetaldehyde to form a white crystalline addition compound, insoluble in ethyl alcohol and ether. This bisulfite addition compound is frequendy used to isolate and purify acetaldehyde, which may be regenerated with dilute acid. Hydrocyanic acid adds to acetaldehyde in the presence of an alkaU catalyst to form cyanohydrin the cyanohydrin may also be prepared from sodium cyanide and the bisulfite addition compound. Acrylonittile [107-13-1] (qv) can be made from acetaldehyde and hydrocyanic acid by heating the cyanohydrin that is formed to 600—700°C (77). Alanine [302-72-7] can be prepared by the reaction of an ammonium salt and an alkaU metal cyanide with acetaldehyde this is a general method for the preparation of a-amino acids called the Strecker amino acids synthesis. Grignard reagents add readily to acetaldehyde, the final product being a secondary alcohol. Thioacetaldehyde [2765-04-0] is formed by reaction of acetaldehyde with hydrogen sulfide thioacetaldehyde polymerizes readily to the trimer. 

Substances that form carbanions, such as nitro compounds, hydrocyanic acid, malonic acid, or acetylacetone, react with vinyl ethers in the presence of water, replacing the alkyl group under mild conditions (245). 

Formamide decomposes thermally either to ammonia and carbon monoxide or to hydrocyanic acid and water. Temperatures around 100°C are critical for formamide, in order to maintain the quaUty requited. The lowest temperature range at which appreciable decomposition occurs is 180—190°C. Boiling formamide decomposes at atmospheric pressure at a rate of about 0.5%/min. In the absence of catalysts the reaction forming NH and CO predominates, whereas hydrocyanic acid formation is favored in the presence of suitable catalysts, eg, aluminum oxides, with yields in excess of 90% at temperatures between 400 and 600°C. 

Methanol can be converted to a dye after oxidation to formaldehyde and subsequent reaction with chromatropic acid [148-25-4]. The dye formed can be deterruined photometrically. However, gc methods are more convenient. Ammonium formate [540-69-2] is converted thermally to formic acid and ammonia. The latter is trapped by formaldehyde, which makes it possible to titrate the residual acid by conventional methods. The water content can be determined by standard Kad Eischer titration. In order to determine iron, it has to be reduced to the iron(II) form and converted to its bipyridyl complex. This compound is red and can be determined photometrically. Contamination with iron and impurities with polymeric hydrocyanic acid are mainly responsible for the color number of the merchandized formamide (<20 APHA). Hydrocyanic acid is detected by converting it to a blue dye that is analyzed and deterruined photometrically. 

In another DMF process, hydrocyanic acid reacts with methanol ia the presence of water and a titanium catalyst (16), or ia the presence of dimethylamine and a catalyst (17). 

Irradiation of ethyleneimine (341,342) with light of short wavelength ia the gas phase has been carried out direcdy and with sensitization (343—349). Photolysis products found were hydrogen, nitrogen, ethylene, ammonium, saturated hydrocarbons (methane, ethane, propane, / -butane), and the dimer of the ethyleneimino radical. The nature and the amount of the reaction products is highly dependent on the conditions used. For example, the photoproducts identified ia a fast flow photoreactor iacluded hydrocyanic acid and acetonitrile (345), ia addition to those found ia a steady state system. The reaction of hydrogen radicals with ethyleneimine results ia the formation of hydrocyanic acid ia addition to methane (350). Important processes ia the photolysis of ethyleneimine are nitrene extmsion and homolysis of the N—H bond, as suggested and simulated by ab initio SCF calculations (351). The occurrence of ethyleneimine as an iatermediate ia the photolytic formation of hydrocyanic acid from acetylene and ammonia ia the atmosphere of the planet Jupiter has been postulated (352), but is disputed (353). 

Mandelic acid is best prepared by the hydrolysis of mandeloni-trile with hydrochloric acid. The mandelonitrile has been prepared from amygdalin, by the action of hydrocyanic acid on benzaldehyde, and by the action of sodium or potassium cyanide on the sodium bisulfite addition product of benzaldehyde. ... 

The excess nitric acid is used in order to oxidize unchanged crotonic acid. Since hydrocyanic acid may be evolved the operation should be carried out under a hood. 

The first methacrylic esters were prepared by dehydration of hydroxyisobutyric esters, prohibitively expensive starting points for commercial synthesis. In 1932 J. W. C. Crawford discovered a new route to the monomer using cheap and readily available chemicals—acetone, hydrocyanic acid, methanol and sulphuric acid— and it is his process which has been used, with minor modifications, throughout the world. Sheet poly(methyl methacrylate) became prominent during World War II for aircraft glazing, a use predicted by Hill in his early patents, and since then has found other applications in many fields. 

Acetylene, fulminic acid (produced in ethanol - nitric acid mixtures), ammonia Acetic acid, acetone, alcohol, aniline, chromic acid, hydrocyanic acid, hydrogen sulphide, flammable liquids, flammable gases, or nitratable substances, paper, cardboard or rags Inorganic bases, amines Silver, mercury... 

Chemical Designations - Synonyms Hydrocyanic acid Prussic acid Chemical Formula NCH. Observable Characteristics - Physical State (as shipped) Liquid Color Colorless to bluish white Odor Characteristic sweetish, like almond. 

Chemical Designations - Synonyms Hydrocyanic acid Chemical Formula NaCN. 

Observable Characteristics - Physical State (as normally shipped) Solid Color. White Odor. Odorless when dry. When moist it has a slight odor of hydrocyanic acid. 

Girgensohnia spp. G. diptera Bge. contains N-methylpiperidine and dipterine, CHH14N2, m.p. 87-8°, [a]D 0° hydrochloride, m.p. 177-8°, picrate, m.p. 189-190°, and picrolonate, m.p. 242-3°, which was later shown to be N-methyltryptamine.i G. oppositiflora Pall, contains N-methylpiperidine and girgensonine, C13H13ON2, m.p. 147-8°, [aJjj 0°. The latter forms a hydrochloride, m.p. 145-8°, and a picrolonate, m.p. 192-4°, and on hydrolysis by alkali yields piperidine, hydrocyanic acid and p-hydroxybenzaldehyde, indicating that it is N-piperidyl-p-hydroxy-phenylacetonitrile, and this has been confirmed by comparison with a synthetic specimen. ( (1) Juraschevski and Stepanova, J. Gen. Chem. Russ., 1939, 9, 2203 Juraschevski, ibid., 1940, 10, 1781. (2) Juraschevski and Stepanova, ibid., 1946, 16, 141). 

A" -3-Ketones do not undergo the exchange reaction with acetone cyanohydrin, although the formation of a 3-cyaiiohydrin has been reported by reaction with hydrocyanic acid. ... 

Mandelic Acid.—The reaction furnishes a simple and general method for obtaining hydroxy-acids from aldehydes or ketones by the aid of the cyanhydrin. The formation of the cyanhydrin may be effected in the manner described or by the action of hydrochloric acid on a mixture of the aldehyde or ketone with potassium cyanide, or, as in the case of the sugais, by the use of liquid hydrocyanic acid and a little amme-nia. 

Hychoxyaldehydes hate been obttiined indirectly by the use of the crystalline compound HCl.HCN (which hychochloiic acid forms with hydrocyanic acid) acting upon a phenol ether,... 

By this process, 4-methylselenazole (2 R = CH3, R = R" = H) could be obtained by the reaction of hydrocyanic acid and hydrogen selenide with chloroacetone. This is the solitary selenazole unsubstituted in the 2-position that is known. The yield, however, was only 2.5% calculated on the chloroacetone used. 

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