XANTHONE (dibenzo-y-pyrone, or diphenylene ketone oxide), C H 0 in organic chemistry, a heterocyclic compound containing the ring system shown below.
By the action of hydroxylamine or phenylhydrazine on aldehydes or ketones, condensation occurs between the carbonyl oxygen of the aldehyde or ketone and the amino group of the hydroxylamine or hydrazine.
Kane; methylethyl ketone and methyl-n-propyl ketone suffer similar condensations to s-triethylbenzene and s-tri-n-propylbenzene respectively.
Considerably greater than the alcohol group. The ketone group corresponds to a thermal effect of 53.52 calories.
It also acts as a chromogenic centre when double bonds or ethylenic linkages are present, as in fluorene ketone or fluorenone.
Normal values of K were given by nitrogen peroxide, N204, sulphur chloride, S 2 C1 21 silicon tetrachloride, SiC1 4, phosphorus chloride, PC1 3, phosphoryl chloride, POC1 31 nickel carbonyl, Ni(CO) 4, carbon disulphide, benzene, pyridine, ether, methyl propyl ketone; association characterized many hydroxylic compounds: for ethyl alcohol the factor of association was 2.74-2.43, for n-propyl alcohol 2.86-2.72, acetic acid 3.62 -2.77, acetone 1 .
By the direct action of hydroxylamine on a methyl alcohol solution of mesityl oxide in the presence of sodium methylate a hydr oxylamino - ketone, diacetone hydroxylamine, (CH 3) 2 C(Nhoh) CH20OCH3,is formed.
ACETOPHENONE, or PHENYL-METHYL KETONE, C8H8O or C6H5CO.CH3, in chemistry, the simplest representative of the class of mixed aliphatic-aromatic ketones.
Darzens (Comptes Rendus, 1904, 139, p. 1214) prepares esters of disubstituted glycidic acids, by condensing the corresponding ketone with monochloracetic ester, in the presence of sodium ethylate.
Our knowledge of the chemical structure of the monosaccharoses may be regarded as dating from 1880, when Zincke suspected some to be ketone alcohols, for it was known that glucose and fructose, for example, yielded penta-acetates, and on reduction gave hexahydric alcohols, which, when reduced by hydriodic acid, gave normal and secondary hexyliodide.
He prepared the cyanhydrins of glucose and fructose, hydrolysed them to the corresponding oxy-acids, from which the hydroxy groups were split out by reduction; it was found that glucose yielded normal heptylic acid and fructose methylbutylacetic acid; hence glucose is an aldehyde alcohol, CH 2 OH (CH OH) 4 CHO, whilst fructose is a ketone alcohol CH 2 OH (CH OH) 3 CO.
Glycerin appears to yield, on mild oxidation, an aldehyde, CH20H CH(OH) CHO, and a ketone, CH 2 OH CO CH 2 OH, and these condense as shown in the equation: CH 2 OH CH (OH) CHO + CH 2 OH [[Coch 2 Oh = Ch20h Ch(Oh) Ch(Oh) Ch(Oh) Co.Ch20h+H20]].
The trioses are the aldehyde and ketone mentioned above as oxidation products of glycerin.
The ketone, dihydroxyacetone, CH 2 OH CO CH 2 OH, was obtained by Piloty by condensing formaldehyde with nitromethane, reducing to a hydroxylamino compound, which is oxidized to the oxime of dihydroxyacetone; the ketone is liberated by oxidation with bromine water: 3H CHO + CH 3 NO 2 -- (CH 2 OH) 3 C NO 2 - (CH 2 OH) 3 C NH OH -- (CH 2 OH) 2 C: NOH - > (CH20H)2CO.
The ketone is also obtained when Bertrand's sorbose bacterium acts on glycerol; this medium also acts on other alcohols to yield ketoses; for example: erythrite gives erythrulose, arabite arabinulose, mannitol fructose, &c.
Anthracene has also been obtained by heating ortho-tolylphenyl ketone with zinc dust C6H4(CH CH =H20+C6H4 I)C6H4.
Oxy-acids are carboxylic acids which also contain a hydroxyl group; similarly we may have aldehyde-acids, ketone-acids, &c. Since the more important acids are treated under their own headings, or under substances closely allied to them, we shall here confine ourselves to general relations.
It behaves more as a ketone than as a quinone, since with hydroxylamine it yields an oxime, and on reduction with zinc dust and caustic soda it yields a secondary alcohol, whilst it cannot be reduced by means of sulphurous acid.
It is a gas at ordinary temperature, and may be liquefied, the liquid boiling at -5° C. It combines with acetyl chloride in the presence of zinc chloride to form a ketone, which on warming breaks down into hydrochloric acid and mesityl oxide (I.
A Klages (Ber., 1902, 35, pp. 2633 et seq.) has shown that if one uses an excess of magnesium and of an alkyl halide with a ketone, an ethylene derivative is formed.
The reaction appears to be perfectly general unless the ketone contains two ortho-substituent groups.
If the groups R and R' are identical, the ketone is called a simple ketone, if unlike, a mixed ketone.
Sodium amalgam reduces them to secondary alcohols; phosphorus pentachloride replaces the carbonyl oxygen by chlorine, forming the ketone chlorides.
With nitrous acid (obtained from amyl nitrite and gaseous hydrochloric acid, the ketone being dissolved in acetic acid) they form isonitroso-ketones, R CO CH:NOH (L.
For dimethyl ketone or acetone, see Acetone.
Diethyl ketone, (C2H5)2 CO, is a pleasant-smelling liquid boiling at 102.7° C. With concentrated nitric acid it forms dinitroethane, and it is oxidized by chromic acid to acetic and propionic acids.
The first compound, containing a group COH, or more explicitly 0 = CH, is an aldehyde, having a pronounced reducing power, producing silver from the oxide, and is therefore called propylaldehyde; the second compound containing the group - C CO C - behaves differently but just as characteristically, and is a ketone, it is therefore denominated propylketone (also acetone or dimethyl ketone).
These alkyl substitution products are important, for they lead to the synthesis of many organic compounds, on account of the fact that they can be hydrolysed in two different ways, barium hydroxide or dilute sodium hydroxide solution giving the socalled ketone hydrolysis, whilst concentrated sodium hydroxide gives the acid hydrolysis.
Ketone hydrolysis,- CH3ï¿½COï¿½C(XY)ï¿½C02C2H5-jCH3ï¿½COï¿½CH(XY)+C2HSOH+C02; Acid hydrolysis:- CH 3 ï¿½COï¿½C(XY) C02C2H5--)CH3.
It may be prepared by distilling diphenylene ketone over zinc dust, or by heating it with hydriodic acid and phosphorus to 150-160° C.; and also by passing the vapour of diphenyl methane through a red hot tube.
It crystallizes in colourless plates, possessing a violet fluorescence, melting at 112-113° and boiling at 293-295° C. By oxidation with chromic acid in glacial acetic acid solution, it is converted into diphenylene ketone (C8H4)2 CO; whilst on heating with hydriodic acid and phosphorus to 250-260° C. it gives a hydro derivative of composition C13H22.
BENZOPHENONE (DIPHENYL KETONE), C 6 H 5 CO.
Tetramethyl-diamido-benzophenone or Michler's ketone, CO[C6H4N (CH3)2]2, melting at 173°, is of technical importance, as by condensation with various substances it can be made to yield dye-stuffs.
ACETONE, or DIMETHYL KETONE', CH3.CO.CH3, in chemistry, the simplest representative of the aliphatic ketones.
Cyclo-hexanol, CcHiiOH, is produced by the reduction of the corresponding ketone, or of the iodhydrin of quinite.
Quinite (cyclo-hexanediol-i 4) is prepared by reducing the corresponding ketone with sodium amalgam, cis-, and trans-modifications being obtained which may be separated by their acetyl derivatives.
It forms a benzal compound, and gives an oyxmethylene derivative and cannot be oxidized to an acid, reactions which point to it being a ketone containing the grouping -CH 2 CO-.
Mayer (Ann., 18 93, 2 75, p. 363) obtained azelain ketone, C,H140, a liquid of peppermint odour.