A manual of elementary chemistry : theoretical and practical / by George Fownes.

  • Fownes, George, 1815-1849.
Date:
1873
Catalogue details

Licence: Public Domain Mark

Credit: A manual of elementary chemistry : theoretical and practical / by George Fownes. Source: Wellcome Collection.

    956/1062
    Derivatives of Urea containing Alcohol-radicals. Ethyl-urea, C3H8N20 = CH3(C2H5)N20, is produced bypassing cyanic acid vapour into a solution of ethylamine. The liquid becomes not, and deposits, after evaporation, fine crystals of ethyl- urea : C2H7N -f CNHO = C3H8N20. This substance may also be prepared by treating cyanic ether with ammonia: CN(C2H-)0 -j- NH3 = C3HsN20. It is very soluble in water and alcohol: the concentrated aqueous solution, unlike that of ordinary urea, yields no precipitate with nitric acid ; but on gently evaporating the mixture, a very soluble crystalline nitrate of ethyl-urea is obtained. Boiled with potash, it yields a mixture of 1 molecule of ammonia and 1 molecule ethylamine: C3H8N20 + 2KHO = K2C03 -f NH3 + C2ELN. Biethyl-urea, C5H12N20 = CH2(C2H5)2]Sr20.—Diethylamide be- haves with cyanic acid like ammonia and ethylamine, giving rise to diethyl-urea. A similar but not identical substance is formed by the action of cyanic ether upon ethylamine: CN(C2H5)0 + C2HrN = C5Hl2N20. The diethyl-ureas are very crystailisable, and readily form crystalline nitrates. Boiled with potash, they yield, the former 1 molecule of diethylamine and 1 molecule of ammonia: CH2(C2HB)2N20 + 2KHO = K2C03 + NH(C2Hfi)2 + NH3; the latter, pure ethylamine: CH2(C2H5)2N20 + 2KHO = K2C03 + 2NH2(C2H6). Metlujl-urea, CH3(CH3)N20, dimethyl-urea, CH2(CH2)2N20, and methyl-ethyl-urea, CH2(CH3)(C2H,)N20, are obtained by similar processes, the last by the action of methyl cyanate on ethylamine. Of amyl-urea, C6Hl4N20, two modifications are known, viz.. primary amyl-urea, CH3(CfiH11)N20, prepared like ethyl-urea, and secondary amyl-urea, or methyl-butyl-urea, CH2(CH3)(C4H9)N20, obtained by the action of ammonia on amylene cyanate. AMIDES DERIVED PROM ACIDS OF HIGHER ATOMICITY. Our knowledge of these amides is somewhat limited: we shall notice only those derived from malic and from citric acid. Malic acid (OjH302)'(OH)3, which is triatoroic and bibasic, forms an acid amide and a neutral amide: (OH (OH (C4H302' \ OH (C4H302)' NH2 (C4H302)' NH, ( OH ( NH2 Mnlamic acid. Malumide. Malamide is deposited in small crystals, when ammonia-gas is passed into an alcoholic solution of ethylic malate :