Journal of the Chemical Society 1913./I. [antikvár]

JOURNAL of THE CHEMICAL SOCIETY, ABSTRACTS OF CHEMICAL PAPERS PUBLISHED IN BRITISH AND FOREIGN JOURNALS. PART I. Organic Chemistry. Preparation of A«y-Butadiene and its Homologues. Badische Anilin- Soda Fabrik (D.R.-P. 252499).—When hydrogenated hydrocarbons of the benzene series containing at least one double bond are heated at high temperatures at the ordinary or (preferably) reduced pressures with an indifferent gas (such as nitrogen), they yield derivatives of butadiene. Isoprene is thus obtained from the lower-boiling fractions furnished by the decomposition of 1-methyl-A'-c2/c?ohexenej or of l-methylci/c?ohexan-2-ol, whilst C2/ciohexene yields A^v butadiene (erythrene), and l-methyl-A^-ci/ciopentene furnishes piperylene, CHs-CHICH-CHICHg. F. M. G. M. Preparation of Isoprene. Badische Anilin- Soda-Fabrik (D.R.-P. 251216).—When as-dimethylallene (b. p. 39—41°) is dropped on to strongly heated aluminium oxide, preferably under a pressure of about 20—30 mm., it is converted into pure isoprene ; the aluminium oxide can be replaced by other catalytic agents, and the formation of higher polymerides must be avoided. P. M. G. M. Preparation of /3y-Dimethylerythrene. Farbenpabriken vorm. FaiEDR. Bayer & Co. (D.R.-P. 253081. Compare A., I9I2, i, 741).— The preparation of /3y-dimethylerythrene by heating pinacone (1 part) with dilute sulphuric acid (10 parts) is described in the literature; it is now found that the most favourable proportions are 1 part of sulphuric acid (20%) to 10,000 parts of pinacone heated at 130—140°, VOL CTV. i. h i. 2 ABSTRACTS OF CHEMICAL PAPERS. when a yield of over 70% of /3y-dimethylerythrene is obtained. The sulphuric acid can be replaced by methanedisulphonic or naphthalene-1 : 5-disulphonic acid. F. M. G. M. The History of Distillation and of Alcohol. Hermann Sohelenz {Zeitsch. angew. Ghem., 1912, 25, 2526—2527).—Polemical against von Lippmann (A., 1912, i, 824 ; ii, 897). C. H. D. Preparation of Homologues of Pinacone. Pakbenfabeiken voHM. Feiede. Bayer Co. (D.R.-P. 251330, 251331).—The homologues of pinacone can be readily prepared in satisfactory yield by the action of aluminium amalgam on the homologues of acetone. yh-Diethylhexane-y^-diol, OH-OEtg-CEt^-OH, m. p. 27—28°, b. p. 116—119°/17 mm., is thus obtained from diethyl ketone. yi-Dimethyl-hexane-yi-diol, OH-OMeEt-CMeEt-OH, b. p. 78—7973 mm., is prepared from methyl ethyl ketone, whilst methyl propyl ketone furnishes Se-dijnethyloctane-Be-diol, OH-CMePr«-CMePr»-OH, m. p. 95°, b. p. 116—170°/15 mm. These reactions can be carried out in either benzene or carbon tetrachloride solutions. II. States that magnesium and mercuric chloride in the presence of cuprous chloride can replace the aluminium amalgam in these preparations. F. M. G. M. The Formation of Polyatomic Rings. Adolf Fbanke and O. Kienbeegee (Monatsh., 1912, 33, 1189—1203).—In a repetition of the work of Alberti and Smieciuszewski (A., 1906, i, 619) the authors converted aK-dihydroxydecane into the chlorohydrin, but found that the product contained also about 15% of the corresponding dichloride, and that the mixture could not be satisfactorily separated ; the constitution of the chlorohydrin was proved by re-conversion into the glycol. Heating the impure chlorohydrin with sodium hydroxide and sand gave rise to a mixture of substances of high molecular weight, but no indication of the heterocyclic isomerides, Cj^HgoO, described earlier (foe. cit.). Endeavours to prepare cyclic molecules from oK-dibromodecane (Franke and Hankam, A., 1910, i, 460) by the action of ordinary zinc dust in aqueous alcohol produced n-decyl alcohol, whilst the action of sodium in ether gave »i-decane, together with a substance, Cg^H^Q or CjoH^a. silJ^y needles, m. p. 36°. " D. F. T. Halogen Ethers. A. Kaevonen {Chem.Zentr., I9I2, ii, 1266—1271; from Acad. Sci. Fennicae., A, 3, 1—103. Compare A., 1909, i, 202). The boiling points and densities have been determined for a number of carefully purified halogen ethers of the series RO'CHjX, EO-CHj-CHjX, and RO-CHs-OHa-OHgX, where R = H, Me, Et or Pr, and X = C1, Br or I. They have been compared with some ethylene- and trimethylene-halogen hydrins, and with some simple alkyl haloids. In the case of metameric halogen ethers, the removal of the halogen atom from the oxygen atom frequently causes a lowering of the boiling point, but as the molecule becomes more symmetrical with regard to the groups II and (CH2)„X, the boiling point rises. As the distance