FURFURAL (synonym: furfural, the truck of l) — and - furylaldehyde, furan -
2 aldehyde, 2 formylfuran, C5H402, the simplest cyclic aldehyde of a furan row; it is used for synthesis of thiamin (vitamin of Vkh), a number of pharmaceuticals (derivatives of nitrofuran); on the productions connected with its receiving or use can become the reason hron. intoxications.
T. — the light yellow oily explosive liquid which is quickly darkening on light as a result of autoxidation with pungent odor
of fresh rye bread, * °kip 161,7 °,
density at 20 ° [d] of 1,16 g! cm3,
we will well dissolve in alcohol and ether, it is moderate in water. On chemical properties F. it is similar about the benzaljdegi-house (see), gives the reactions typical for aldehydes (see) and connections of an aromatic series (it is nitridden, alkylated, halogenated, etc.). Furfural easily enters condensations with phenols (see), aniline (see) and other aromatic compounds, forming at the same time the painted reaction products that is used for quantitative definition F. and carbohydrates (see). In acidic environment F. it is unstable. Receive F. from pentoses (see) or ggento-zansoderzhashchy raw materials, napr, bran, during the heating with diluted mineral to-tami (especially with sulfuric or salt) therefore there is dehydration of pentose to eliminating of three water molecules and education F.
5 oxymethylfurfural with the properties similar to properties F are formed of hexoses in these conditions. Education F. (see) comes from monosaccharides quickly and quantitatively (from ketosugars F. it is formed in softer conditions, than of aldosa-har) that is also used in many methods of definition of carbohydrates.
T. determine by methods of a chromatography (see) on paper, in a thin coat, etc., by its characteristic absorption in UF-light at 278 nanometers, colorimetric methods (see Colorimetry) by ability to form the painted complexes with cyclic connections (ant-rony, phenol, resorcin, thiobarbituric to - that, etc.) in acid medium.
At hit F. in a human body and animals it is oxidized to pirosliziyevy to - you, edges part F is removed with urine, however. it is allocated in not changed look through kidneys and with expired air.
In pharmaceutical industry F. is a basis for synthesis of nitrofurans (see), derivatives to-rykh Furacilin (see) — 5 nitrofurfurals semicarbazone, furasolidone (see) —] H - (5-nitro-2-furfurylidene) -
Z-aminooksazolidon-2, furadonin (see) —] H - (5-nitro-2-furfurylidene) -
1 aminohydantoin, etc. are applied in medical practice to treatment inf. diseases.
T. use for synthesis of fungicides (see), derivatives of furan, plastic, and also in the woodworking industry as the selective solvent in oil-processing industry, at purification of oils and fats.
Couple F. render irritant action on mucous membranes of respiratory tracts and a conjunctiva; at long steam inhalation F. in high concentration he finds properties of nervous poison, causing spasms and paralyzes.
Hron. poisoning couples F. it is characterized by development of conjunctivitis, emergence of irritation in a throat, cough, the complicated breath, hypersalivation, nausea, dizziness, a headache. Treatment of a symptom tiches to oye.
At inhalation I yes it is necessary to bring the victim to fresh air, to allow to smell spirit of ammonia then appoint inhalation of water vapors with use of infusion of a camomile or weak solution of alcohol, an aerosol of solutions of 0,5% of hydrosodium carbonate or 1% of sodium thiosulphate. The victim needs to provide rest, heat. At a fluid lungs hold the relevant activities (see the Fluid lungs); at heavy intoxication appoint Prednisolonum with antibiotics. Further treatment — symptomatic; the patient shall be transferred to work out of contact with the toxic agent before total disappearance of symptoms of intoxication.
Measures p r about f and l and to t and to and intoxications of a furfuroshaggy hair consist in sealing of the equipment, automation tekhnol. process, effective ventilation, use of the filtering industrial gas masks (see) or respirators (see) with the replaceable filter.
Maximum allowable concentration of vapors F. in air of a working zone of 10 mg/m3.
V. K. Gorodetsky.