An Explosion during the Oxidation of Tetralin with Hydrogen Peroxide in Acetone

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  • markable similarity of the infrared and ultraviolet spectra of these complexes with those of bisdithiobenzilnicke1.

    Received, July 13th, 1964 [Z 783/607 IE] German version: Angew. Chem. 76, 715 (1964)

    -CN -CN -COCH3 -CN -CN

    [ I ] G. N. Schrauzer and V. Muyweg, Z . Naturforsch. 196, 192 (1964). [2] G. N. Schrauzer, V. Muyweg, H . W. Finck, U. Miiller- Wester- hoK and W . Heinrich, Angew. Chem. 76, 345 (1964); Angew. Chem. internat. Edit. 3, 381 (1964). [3] R. B. King, Inorg. Chem. 2, 326 (1963).

    -CN -CH3 Benzyl 114-115 86 -C02CzH5 --H Cyclohexyl 116- 117 62 -CO-CH, -H Cyclohexyl 87-88 57 - CN -N(CH3)2 -CH3 165-166 83 -CN --SCH3 -CH3 120-121 85

    Condensation of Active Methylene Compounds with Isothioamide Groups

    By Dr. K. Hartke [*]

    Instituto Central de Quimica, Universidad Concepci6n (Chile)

    Enol ethers with activating groups (-CN, -COzR, >C=O) in the F-position react with amines to form amino olefins (3). The latter are also readily obtained by condensation o f compounds containing active methylene groups (1) with

    compounds (2) containing the group -N=C-SR (iso- thioamides, isothioureas, or iminothiocarboxylic esters). The condensation takes place without a catalyst by mixing the components in a solvent, e.g. alcohol or ether. With com- pounds containing particularly reactive methylene groups, e . g . malonitrile or dimeric malonitrile, the reaction is fre- quently exothermic. In other cases the reaction mixture is allowed to stand for several hours to days at room tem- perature or is heated for some time on a water bath. Some compounds obtained in this way are given in the Table (structures determined by elementary analyses and infrared spectra; independent synthesis of (3e) [l]).

    + HSR3 x\ SR3 x, P' /CH2 + R - ' Y

    I y X

    [*I Present address: Institut fur Pharmazeutische Chemie und Lebensmittelchemie der Universitat Marburg/Lahn (Germany). [I] Cf. R. Gompper and W. T6pJ7, Chem. Ber. 95, 2871 (1962).

    An Explosion during the Oxidation of Tetralin with Hydrogen Peroxide in Acetone

    By Dr. H. Seidl

    Institut fur Organische Chemie der Universitat Munchen (Germany)

    During the preparation of a-tetralone, tetralin was oxidized with 30 % H202 according to the method of Treibs et al. [I]. On subsequent evaporation of the reaction mixture in vucuo, as the last of the solvent distilled over, the distillation residue exploded with great violence, causing injuries and damage.

    Since the starch-iodide test for free HzOz had been negative, we suspect the formation of acetone peroxides as the cause of the explosion. Other routes to a-tetralone are available[2].

    Received, July 13th, 1964 [Z 785/621 IE] German.version: Angew. Chem. 76, 716 (1964)

    [ I ] W.Treibs, G. Frunke, G. Leichsenring, and H . Roder, Chem. Ber. 86, 616 (1953). [2] E. L. Martin and L. F. Fieser in: Organic Syntheses. Wiley, New York 1943, Coll. Vol. 11, p. 569; R. B. Wagner and H. D. Zook in: Synthetic Organic Chemistry, Ketones. Wiley, New York 1953, p. 316 et seq.

    Radiochemical Hydroxylation of Phenolic Compounds

    By Dr. F. Merger and Dip1.-Chem. D. Grasslin

    Organisches-Chemisches Institut der Universitat Heidelberg (Germany)

    We have found that gallic acid and other phenolic carboxylic acids are hydroxylated at room temperature in water by the action o f 6OCo y-rays. The hydroxylation, which can be carried out on a preparative scale, occurs with remarkable selectivity ortho to existing hydroxyl groups and proceeds more rapidly in the presence of oxygen than when oxygen is excluded. nz-Dihydroxybenzoic acids are particularly easily hydroxylated between the two hydroxyl groups. Irradiation of a 1 % aqueous solution of gallic acid saturated with oxygen (dosage rate of the 6OCo y-ray source: 4 . 0 6 ~ 105 r/h; irradiation time: 300 h) gave 2,3,4,5-tetrahydroxy- benzoic acid in 52.8 % yield with a G-value [*] of 0.22; separation of the residual gallic acid was achieved by frac- tional cr) stallization and preparative chromatography. The G-values for some other phenolic carboxylic acids are con- siderably higher. Nitrophenols are hydroxylated much faster than phenolic carboxylic acids. p-Nitrophenol affords 4-nitrocatechol, and 4- or 5-nitropyrogallol give the hitherto unknown 1,2,3,4- tetrahydroxynitrobenzene (G = 1.4 1).

    Received, July 20th. 1964 [Z 789/619 IEI German version: Angew. Chem. 76, 752 (1964)

    [*I The G-value indicates the number of molecules formed per 100 eV.

    t-Butylaluminum Compounds

    By Dr. H. Lehmkuhl

    Max-Planck-Institut fur Kohlenforschung, Miilheim/Ruhr (Germany)

    The addition of al-H onto olefins occurs predominantly according to Markownikoffs rule [ l , 21; the reaction of al-H with isobutene thus gives triisobutylaluminum ( I ) , but no tri-t-butylaluminum (2). - / al-CH2-CH(CH3)2 ( I )

    (2) al-H + HZC=C(CHJz

    al-C(CH3)s

    It was expected [2] that (2) would be unstable and would rearrange to ( I ) via al-H and isobutene. Isomerization to the primary trialkylaluminum occurs with triisopropyl- aluminum [3]. We found, however, that (3), the etherate of (2), which is produced in 75 % yield by the reaction in ether of t-butylmagnesium chloride with AlCI3 in a molar ratio of 3: 1, is actually quite stable.

    13) [ H3C - !?+A 1 . (C 2H5) ,O 640 Angew. Chem. internut. Edit. 1 Vol. 3 (1964) 1 No. 9

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