If alkyl or aryl-ortho-diamines be used azonium bases are obtained.
They add on alkyl iodides readily, forming alkyl azonium salts.
The hydrogen of the hydroxyl group in phenol can be replaced by metals, by alkyl groups and by acid radicals.
The alkyl derivatives may be obtained by heating phenol with one molecular proportion of a caustic alkali and of an alkyl iodide.
Alkyl compounds of germanium such as germanium tetra-ethyl, Ge(C2H5)4, a liquid boiling at C., have been obtained.
It is a most important synthetic reagent; with sodium or sodium ethylate it forms sodio-malonic ester, which reacts readily with alkyl halides, forming alkyl malonic esters, which are again capable of forming sodium derivatives, that by further treatment with alkyl halides yield the di-alkyl malonic esters.
These esters are readily hydrolysed and yield the monoand di-alkylimalonic acids which, on heating, are readily decomposed, with evolution of carbon dioxide and the formation of monoand di-alkyl acetic acids.
Carbon bisulphide combines with primary amines to form alkyl dithiocarbamates, which when heated lose sulphuretted hydrogen and leave a residue of a dialkyl thio-urea, CS 2 +2R NH 2 - R NH CSS NH 3 RCS(NHR)2+H2S; or if the aqueous solution of the dithiocarbamate be boiled with mercuric chloride or silver nitrate solution, a mustard oil (q.v.) is formed, R.NH CSS NH3R+HgC12-Hg(R NH CSS)2->2RNCS-}-HgS+H2S.
We may also notice that thio-ethers combine with alkyl iodides to form sulphide or sulphonium compounds, R3; SI.
In fact, the analogy between the alkyl groups and metallic elements forms a convenient basis from which to consider many derivatives.
NH 2; secondary, R2: NH; and tertiary, R3: N; the oxamines, R 3 N :0, are closely related to the tertiary ammonias, which also unite with a molecule of alkyl iodide to form salts of quaternary ammonium bases, e.g.
The amines also exhibit striking differences: in the aliphatic series these compounds may be directly formed from the alkyl haloids and ammonia, but in the benzene series this reaction is quite impossible unless the haloid atom be weakened by the presence of other substituents, e.g.
On the chromophoreauxochrome theory (the nitro group being the chromophore, and the hydroxyl the auxochrome) it is necessary in order to explain the high colour of the metallic salts and the colourless alkyl and aryl derivatives to assume that the auxochromic action of the hydroxyl group is only brought strongly into evidence by salt formation.
The measure of the loss of symmetry associated with the introduction of alkyl groups depends upon the relative magnitudes of the substituent group and the rest of the molecule; and the larger the molecule, the less would be the morphotropic effect of any particular substituent.
Other substituent groups exercise morphotropic effects similar to those exhibited by the alkyl radicles; investigations have been made on halogen-, hydroxy-, and nitro-derivatives of benzene and substituted benzenes.
The N-derivatives are prepared by the action of alkyl halides and acid chlorides on potassium pyrrol.
Beckmann, Ber., 1886, 1 9, p. 9 8 9; 188 7, 20, p. 2580), yielding as final products an acid-amide or anilide, thus: RC(:N OH)R'-RC(OH) :NR' ---> As regards the constitution of the oximes, two possibilities exist, namely >C: NOH, or > C' ?, and the first of these is presumably correct, since on alkylation and subsequent hydrolysis an alkyl hydroxylamine of the type NH 2 OR is obtained, and consequently it is to be presumed that in the alkylated oxime, the alkyl group is attached to oxygen, and the oxime itself therefore contains the hydroxyl group. It is to be noted that the oximes of aromatic aldehydes and of unsymmetrical aromatic ketones frequently exist in isomeric forms. This isomerism is explained by the HantzschWerner hypothesis (Ber., 1890, 23, p. II) in which the assumption is made that the three valencies of the nitrogen atom do not lie in the same plane.
The thiazoles are somewhat basic in character, and combine with the alkyl iodides to form thiazolium iodides.
These salts are like those of tin; and the resemblance to this metal is clearly enhanced by the study of the alkyl compounds.
ALDEHYDES, a class of chemical compounds of the general formula Rï¿½CHO (R=an alkyl or an aryl group).
Soc. chim., 1904 [31, 31, p.1306) prepares aldehydes by the gradual addition of disubstituted formamides (dissolved in anhydrous ether) to magnesium alkyl haloids, the best yields being obtained by the use of diethyl formamide.
In the German Patent 1 57573 (1904) it is shown that by the action of at least two molecular proportions of an alkyl formate on two molecular proportions of a magnesium alkyl or aryl haloid, a complex addition compound is formed, which readily decomposes into a basic magnesium salt and an aldehyde, C H MgBr-f-H000R-ROï¿½CHï¿½C H.
Grignard (Comptes Rendus, 1900 et seq.) showed that aldehydes combine with magnesium alkyl iodides (in absolute ether solution) to form addition products, which are decomposed by water with the formation of secondary alcohols, thus from acetaldehyde and magnesium methyl iodide, isopropyl alcohol is obtained.
Aiphatic Nitro Compounds.-The nitroparaffins may be obtained by the action of the alkyl iodides on silver nitrite (V.
Stannous chloride and hydrochloric acid reduce the nitroparaffins to 0-alkyl hydroxylamines, amines and some ammonia being simultaneously produced (V.
The nitrate of this base (known as nitron) is so insoluble that nitrates may be gravimetrically estimated with its help. These bases combine with the alkyl iodides to yield quaternary ammonium salts.
They combine readily with the alkyl iodides to form alkyl acridinium iodides, which are readily transformed by the action of alkaline potassium ferricyanide to N-alkyl acridones.
The organic derivatives of silicon resemble the corresponding carbon compounds except in so far that the silicon atom is not capable of combining with itself to form a complex chain in the same manner as the carbon atom, the limit at present being a chain of three silicon atoms. Many of the earlier-known silicon alkyl compounds were isolated by Friedel and Crafts and by Ladenburg, the method adopted consisting in the interaction of the zinc alkyl compounds with silicon halides or esters of silicic acids.
Taurke (Ber., 1905, 38, p. 1663) by condensing silicon halides with alkyl chlorides in the presence of sodium: SiC14-1-4R Cl+8Na= SiR 4 +8NaCI; SiHC1 3 +3R.
The normal esters may be prepared by the action of silver carbonate on the alkyl iodides, or by the action of alcohols on the chlorcarbonic esters.
By heating with phosphorus pentachloride an alkyl group is eliminated and a chlorcarbonic ester formed.
ETHYL, in chemistry, the name given to the alkyl radical C 2 H 5.
- Hydrocyanic acid forms two series of derivatives by the exchange of its hydrogen atom for alkyl or aryl groups; namely the nitriles, of type R CN, and the isonitriles, of type R NC. The latter compounds may be considered as derivatives of the as yet unknown isohydrocyanic acid HNC.
They may be prepared by heating the alkyl iodides with potassium cyanide; by heating sulphuric acid esters with potassium cyanide; by distilling the acid-amides with phosphorus pentoxide; and by distilling amines (containing more than five atoms of carbon) with bromine and potash (A.
This reaction shows that the alkyl or aryl group is attached to the carbon atom in the nitrile.
Gautier (Ann., 1869, 151, p. 239) by the action of alkyl iodides on silver cyanide, and the distillation of the resulting compound with potassium cyanide in concentrated aqueous solution: RIR Ag(NC) 2 -)R NC+KAg(NC)2.
This reaction shows that the alkyl or aryl group is linked to the nitrogen atom.
Soc., 1902, 81, p. 1 59 6) who showed that the products obtained by the action of alkyl iodides on the isonitriles in alcoholic solution at 100° C. yield amine hydroidides and formic acid when hydrolysed.
Such a reaction can only take place if the addition of the alkyl group takes place on the nitrogen atom of the isonitrile, from which it follows that the nitrogen atom must be trivalent and consequently the carbon atom divalent.
- Considerable discussion has taken place as to the structure of the metallic cyanides, since potassium cyanide and silver cyanide react with alkyl iodides to form nitriles and isonitriles respectively, thus apparently pointing to the fact that these two compounds possess the formulae KCN and AgNC. The metallic cyanides are analogous to the alkyl isocyanides, since they form soluble double silver salts, and the fact that ethyl ferrocyanide on distillation yields ethyl isocyanide also points to their isocyanide structure.
They may also be prepared by eliminating the halogen hydride from the alkyl halides by heating with alcoholic potash, or with litharge at 220° C. (A.
Chablay, Comptes rendus, 1906, 1 43, p. 123) 2CH 2 :CH CH 2 OH+2NH 3 Na = CH,:CH CH3+CH2:CH CH20Na +NaOH+2NH31 from the lower members of the series by heating them with alkyl halides in the presence of lead oxide or lime: C5H,9-I-2CH31 =2H1+ C 7 H, 4 i and by the action of the zinc alkyls upon the halogen substituted olefines.