Organic chemistry

1887 Journal of the Chemical Society Abstracts  
ORUANIC CHEMISTRY. 5 65 0 r g an i c C h e m i s try, Action of Heat on Heptine. By A. RENARD (Compt. rend., 104. 574--576).--Heptine, C7HI2, boiling at 103-105" was allowed to fall drop by drop into an iron tube which was heated to incipient redness, and was connected at the opposite end with a condensing arrangement. The products are a considerable volume of hydrogen mixed with a small quantity of gaseous hydrocarbons, a small quantity of carbon, and a large proportion of a brownish-yellow
more » ... brownish-yellow liquid which contains a small quantity of pentine, a large proportion of hexine, a small proportion of benzene, and a much larger proportion of toluene. This liquid also contains a considerable fraction boiling above 115", about half of which boils between 115" and 180", leaving a viscous residue which is solid at ordinary temperatures. This fraction has not been examined in detail, but it contains no hydrocarbons of the benzene series. The pentine is either identical or isomeric with the pentine obtained by Greville Williams by the distillation of caoutchouc, or by Tilden in the pyrogenation of terebenthene. Hexine, CGHIo, the lower homologue of heptine. boils at 7@-73", and is soluble in alcohol, ether, and acetic acid ; vapour-density, 2-97. It 566 ABSTRACTS OF CHEMICAL PAPERS. rapidly absorbs oxygen, but exerts no action on ammoniacal cuprous chloride or ammonio-silver nitrate. It is violently attacked by bromine with evolution of hydrogen bromide, but if its ethereal solution is treated with bromine it yields the additive product C6HlOBr2, which after the evaporation of the ether forms a heavy oil, b u t soon decomposes with evolution of hydrogen bromide. Ordinary nitric acid attacks the hydrocarbon violently, but acid of sp. gr. 1.15 acts more gradually with evolution of carbonic oxide and carbonic anhydride, but n o nitrogen oxides, and formation of a solution of formic, acetic, oxalic, and succinic acids. Gaseous hydrogen chloride produces a deep blue coloration. Hexine does not, like heptine, form a crystallisable hydrate with water. I n contact with sulphuric acid, it polyrnerises with development of heat, and when the supernatant layer is distilled it yields dihexine, C12H2", a colourless liquid which boils a t 210-215", does not alter in contact with the air, and is not attacked by sulphuric acid. The principal products of the action of heat on heptine are hydrogen and toluene, together with smaller proportions of the lower homolopues of heptine, pentine, and hexine. The benzene is doubtless a product of the decomposition of some of the hexine. C. H. B. Bismuth Thiocyanate. By G. BENDER (Rer., 20,(723)(724)(725)(726) .-Bismuth thiocyanate, Bi(CNS)3, is prepared by treating bismuth hydroxide with very dilute hydrogen thiocyanate solution (sp. gr. = 1.006). The solution takes place very slowly, and a small quantity of a yellow substance separates, probably consisting of basic salts (Meitzendorf (Ann. Phys. Chem., 56,63) . The product is evaporated in a water-bath, when a red, amorphous substance separates ; on cooling, pure bismuth thiocyanate Separates in aggregates of rather large crystals mostly of a bright-orange colour, but also partly ambercboloured. The crystals are rhombic ; a : b : c = 0.76134 : 1 : 0.284'23. It is decomposed by cold water into a yellow, amorphous substance and a red solution; when heated a t 80°, it also decomposes. Cold nitric acid dissolves it with a red colour ; in a short time a n evolution of gas takes place, and a clear solutiou is formed containing all the sulphur in the form of sulphuric acid. N. H. M. Action of Potassium Permanganate on Dextrose in Neutral Solution. By A. SMOLKA (Monutsh. Chew,., 8,l-26 ).-When dextrose is boiled with excess of potassium permanganate, it is completely oxidised to water and carbonic anhydride with sepayation of a potassium hydroinanganite, KH3Mn4010. With excess of permanganate in the cold the action is the same, a trace of oxalic acid, however, being also formed. By successively decreasing the amount of potassium peismanganate, and allowing the action t o take place a t the ordinary temperature, there are obtained, in addition to water and carbonic anhydride, oxalic acid and formic acid, or the two latter alone, and a quantity of dextrose remains unaltered, depending on the amount of oxidising agent employed. The permanganate is reduced, partly to manganic, and partly to mangnnous oxide. The relative amounts of the products
doi:10.1039/ca8875200565 fatcat:v4onekjdvng6hmzcknuvtcxh6i