The corresponding dimethyl carbon-dibromide, or methyl brom-acetol, CH3.CBr2.CH3, prepared from acetone and phosphoric chloro-bromide: (CH3)2CO+PC13Br2 = POCI, + (CH3)2CBr2, boils between 113° and 116°, and has at 0° sp. gr. 1815. = 446. Thiacetone is obtained as the doubled molecule, C6H12S2 on bringing together the higher sulphides of CH3 >C<S>C<CH phosphorus and acetone. The reaction: 2P2S+ 10C3H6O2P2O5 + 5(C3H6)2S2, which, however, is accompanied by other processes, evolves much heat. By fractional distillation the double thiacetone is obtained as a yellowish oil of extremely unpleasant and persistent odour. It boils between 183° and 185°, and has the vapour density 5.08. 447. On allowing acetone saturated with ammonia gas to stand some time, as by heating the mixture to 100° in sealed tubes, various basic nitrogen compounds are obtained, which probably possess some similarity with the aldehyde derivatives obtained in analogous manner, but require closer investigation. An acetone solution containing hydrocyanic acid is converted on heating with hydrochloric acid into a-oxyisobutyric acid (see this). The reaction completely corresponds with the conversion of aldehydes into acids of the lactic series. 448. Numerous halogen substitution products of acetone are known monochlor acetone, CH¿CIO or CH3.CO.CH2Cl, and two isomeric dichlor acetones, CH3.CO.CHCI, and CH2Cl.CO.CH2Cl; a trichlor acetone, C3HClO3; tetrachlor acetone, C3H2.Cl4O; pentachlor acetone, CHCI.CO.CCI,; and perchlor acetone, CC13.CO.CC13. They are all liquids of powerfully irritating odour. From acetone itself only the first four are prepared, the two latter being obtained from other organic compounds, such as citric acid. The more interesting of them will be described later. Some bromine and iodine substitution products of acetone are also known. Homologues of Acetone. 449. The formula C,H,O only corresponds to a single ketone, that isomeric with butyric aldehyde, methyl-ethyl ketone : CH3.CO.CH2.CH3, which is obtained by oxidation of secondary butylic alcohol (§ 169). It is also obtained by double decomposition of acetic chloride and zinc ethyl : 2CH3.COCI + Zn(C2H5)2 = ZnCl2 + 2CH3.CO.C2H5, as also by boiling ethylic methyl aceto-acetate with an alkali : CH3.CO.CH.(CH3).CO.O.C,H + 2KOH = K,CO3 + HỌ.CgHs + CH3.CO.CH2.CH3, 5 and is contained in small quantity in the crude acetone prepared from acetates. Methyl-ethyl ketone is a colourless liquid of agreeable odour, of sp. gr. 8125, which boils at 81°. On oxidation it yields only acetic acid : 450. Three isomeric ketones, C5H100, correspond to valeric aldehyde. 1. Methylpropyl ketone, CH3.CO.CH2.CH2.CH3, is obtained by dry distillation of a mixture of an acetate and butyrate : CH3.CO.OM + CH3.CH2.CH2.CO.OM = M2CO2 also obtained on the careful oxidation of propyl-methyl carbinol, into which it is converted by action of nascent hydrogen (§ 170), and also formed by the decomposition of ethylic ethyl aceto-acetate by potassic hydrate : CO.CH, CO.CH3 CH.C2H + 2KOH= K2CO3 + HO.C2H5 + CH2.C2H5 CO.O.C -5 It is a colourless liquid, of agreeable acetone-like smell, which at 13° has sp. gr. 8132 and boils at 101°. It yields a beautifully crystalline compound with hydric sodic sulphite. By oxidation it gives acetic and propionic acids. CH3 2. Methyl-isopropyl ketone, CH3.CO.CH CH3, is obtained by the decomposition of ethylic dimethyl aceto-acetate: CH3.CO.C(CH3)2.CO.O.C2H5. It boils at 93.5°, and has at 13° the sp. gr. 8099. 3. Diethyl ketone, or propione, CH3.CH2.CO.CH2.CH3, is obtained by the dry distillation of propionates: (C2H5.CO.O),Ca = CO3Ca + (C2H5)1⁄2CO; . by decomposition of propionic chloride by zinc ethyl : 2C2H.CO.Cl + Zn(C2H5)2 = ZnCl2 + 2C2H5.CO.C2H5; and by the action of carbonic oxide on the product, containing potassium ethyl, of the action of potassium on zinc ethyl : CO+2K.C2H5 = K2+ CO.(C2H5)2. It is also prepared by the careful oxidation of diethoxalic acid: It has sp. gr. 813 at 20°, and boils at 101°. It is converted into propionic and acetic acids on energetic oxidation. It gives no compounds with the hydric sulphites. 451. Hex-carbon ketones, C6H12O. Six of these bodies are possible-namely, four methyl-butyl ketones, CH3.CO.C,H,, and two ethyl-propyl ketones, C2H.CO.C2H,. Methyl-butyl ketone, CH3.CO.CH2.CH2.CH2.CH3, is obtained by KETONES. 283 the oxidation of methyl-butyl carbinol (§ 171). It boils at 127° and has sp. gr. 8298. Methyl-trimethyl carbin-ketone, pinacoline, CH3.CO.C(CH3)3, is prepared by heating pinacone with dilute sulphuric acid or with concentrated acetic acid. It is a colourless oil, boiling at 105°; on oxidation it yields trimethacetic acid; nascent hydrogen converts it into pinacoline alcohol, CH13.OH. A ketone of this formula, boiling at 128°, is obtained as a bye product in the dry distillation of calcic butyrate. It has at 0° sp. gr. 833, and is probably ethyl-propyl ketone: CH3.CH2.CO.CH2.CH2.CH3. 14 452. The main product of the dry distillation of calcic butyrate is dipropyl ketone, or butyrone, C,H1,0 = (CH3.CH2.CH2)2CO. It boils at 144°-145°, and has at 20° the sp. gr. 82. By chromic acid and sulphuric acid it is oxidised to butyric and propionic acids, by fuming nitric acid to nitro-propionic acid, C3H5(NO2)O2. Diisopropyl ketone, or isobutyrone, [(CH3)2.CH]2CO, is obtained by the careful oxidation of diisopropyl oxalic acid and by the dry distillation of calcic isobutyrate. It distils at 123°-125°, and is oxidised by chromic acid to isobutyric, acetic, and carbonic acids. Methyl-amyl ketone, CH3.CO.CH2.CH2.CH2.CH2.CH3, is obtained by the oxidation of methyl-amyl carbinol, as an agreeable-smelling liquid, boiling at 155°-156°, which unites with the alkaline hydric sulphites and is oxidised to acetic and normal valeric acids. Methyl-isoamyl ketone, CH3.CO.CH2.CH2.CH:(CH3)2, is obtained by the action of zinc amyl on acetic chloride or of isocaproic chloride on zinc methyl: 2CH3.CO.Cl + Zn[CH2.CH2.CH: (CH3)2]2 = It boils at 144° and has at 0° sp. gr. 829. It unites with hydric sulphites, and yields acetic and isovaleric acid on oxidation. 453. Methyl-hexyl ketone, or methyl ananthone, CH160 or CH3.CO.CH2.CH2.CH2.CH2.CH2.CH3, is obtained by dry distillation of a mixture of calcic acetate and oenanthate, and by the oxidation of methyl-hexyl carbinol (§ 173). It boils at 171° and yields on oxidation acetic and caproic acids. The sp. gr. 818. An isomeric ketone, termed methyl butyrone, occurs amongst the bye products of the preparation of butyrone, as a liquid boiling at 180°. It is probably a propyl-butyl ketone, C3H7.CO.C4H9. 454. The body termed valerone, obtained by the dry distillation of calcic isovalerate, is undoubtedly diisobutyl ketone: [(CH3)2.CH.CH2]1⁄2CO. It is an oily liquid, boiling at 181°-182°, and of sp. gr. 823 at 20°. 454a. Methyl-octyl ketone, CH,.CO.CH2.C-H15, is prepared by the action of alcoholic potash on ethyl-heptyl aceto-acetate. It is a liquid boiling at 214° and of sp. gr. 8294 at 17.7°. 455. Methyl-nonyl ketone, CH22O = CH3.CO.C,H19, forms the main constituent of ethereal oil of rue (Ruta graveolens), and is ob tained therefrom by shaking with a concentrated solution of hydric sodic sulphite in form of the crystalline compound from which it is obtained in the free state by treatment with alkaline carbonates. It is also obtained by the dry distillation of a mixture of calcic acetate and caproate. At ordinary temperatures it is a colourless oil with blue fluorescence, of sp. gr. 8268, which, on cooling, solidifies in leafy crystals; it melts at + 15°, and boils at 225°-226°. Isomeric with this is caprone, probably normal diamyl ketone, (C5H11)2: CO, obtained by the dry distillation of calcic caproate. It boils at 220°-221°, has at 0° sp. gr. 822, and solidifies to a crystalline mass on cooling. Enanthone, C13H26O = (C6H13)20, is a dihexyl ketone, which is obtained by the dry distillation of potassic oenanthate. It crystallises in leafy crystals, melting at 30°, of sp. gr. 824, which boil at 254°-255°. 455a. Isomeric with this is methyl-undecyl ketone: CH3.CO.C11H239 prepared by the dry distillation of a mixture of baric laurate and acetate under reduced pressure. It melts at 28°, boils at 195.5° under 100 mm. pressure and at 263° at ordinary atmospheric pres sure. Baric caprylate yields on decomposition, at high temperatures, a diheptyl ketone, C15H300 = (C,H),CO. It crystallises in leafy crystals, melts at 40°, and boils at 278°. 4556. The isomeric methyl-tridecyl ketone: C15H300 CH3.CO.C13H27, = is prepared by the dry distillation of a mixture of baric myristate and acetate under reduced pressure. It melts at 39°, boils at 223.5° under 110 mm. pressure and at 294° under normal pressure. = 455c. Methyl-pentadecyl ketone, C17H340 CH3.CO.C15H319 obtained on dry distillation of mixed acetate and palmitate of barium under reduced pressure, melts at 48°, boils at 246° under 110 mm. pressure and at 319°-320° under atmospheric pressure. Methyl-diheptyl-carbin-ketone, CH3.CO.C(C,H15)2, isomeric with the preceding, is obtained by the action of alcoholic potash on ethylic diheptyl aceto-acetate; it is a colourless liquid, boiling at 300°-304°, and of sp. gr. 826 at 17°. 455d. Methyl-heptadecyl ketone, C19H38O = CH3.CO.C17H35, prepared as above from baric stearate and acetate, melts at 55.5°, and boils at 266.5° under 110° mm. pressure. GLYCOL DERIVATIVES. Compounds of the Diad Alcohol Radicals, CnH2n 456. By replacement of two of the hydrogen atoms of a paraffin on two different carbon atoms there results derivatives of the divalent alcohol radicals, CnH2n, the olefines, whose chief representatives are the hydrates, the diacid alcohols or glycols, CnH2n(OH)2. The first member of the series must be a dicarbonide, ethylene glycol, C2H,(OH)2, a double primary diacid alcohol: The second member, C3H6(OH)2, is known in two isomers, of which the one is a primary-secondary, the other a diprimary, glycol: Of the tetracarbon glycol, C4H,(OH)2, six isomers are possible, namely: It is self-evident that for every additional carbon atom the number of possible isomers must increase in rapid progression, and that still further complications in the character of the substitution must ensue, as, for instance, secondary-tertiary glycols. Of the ditertiary the first member, the hexcarbon acetone-pinacone or tetramethylethylene glycol, is known: 457. In by far the largest number of known glycols one of the hydroxyl groups occupies the primary position, i.e. is on a terminal |