white needles. When rapidly heated, it melts at 150-151°, but when the temperature is gradually raised it darkens and decomposes at 140-143°, giving off hydrogen cyanide. 0.1780 gave 11.9 c.c. moist nitrogen at 15° and 746 mm. N=7.68. C19H15ON2Br requires N = 7.62 per cent. Cinnamylidene-1-bromo-2-naphthylamine, C10H&Br N.CH CH:CH·C ̧H5, readily dissolves in benzene, alcohol, or chloroform, but is less soluble in light petroleum; it crystallises in golden-yellow needles and melts at 126°. 0.1528 gave 0.0840 AgBr. Br= 23.90. C1,H1NBr requires Br= 23.81 per cent. The hydrocyanide, which is rapidly produced from the preceding compound by the action of hydrogen cyanide, crystallises from benzene in white, lustrous leaflets melting at 142–143°. Benzylidene-1-chloro-2-naphthylamine crystallises from light petroleum in pale yellow leaflets melting at 98-99o. 0.1041 gave 0.0584 AgCl. Cl = 13·87. C17H12NCI requires Cl = 13.37 per cent. The hydrocyanide crystallises in convoluted aggregates of small scales and melts at 76-77°. 0.2329 gave 19.2 c.c. moist nitrogen at 16° and 761 mm. N = 9.62. C18H3N2CI requires N = 9.57 per cent. Cuminylidene-1-chloro-2-naphthylamine slowly separates in brown crusts on allowing the glacial acetic acid solution of its generators to evaporate at the ordinary temperature; when purified by crystallisation from light petroleum, it forms brownish-yellow leaflets melting at 85°. 0.1435 gave 0.0641 AgCl. Cl=11·06. C20H18NCI requires Cl=11.54 per cent. The hydrocyanide crystallises from methyl alcohol in transparent, colourless leaflets and melts at 117°. 0.1485 gave 10.9 c.c. moist nitrogen at 16° and 760 mm. N=8·64. C21H1N,Cl requires N = 8.37 per cent. Cinnamylidene-1-chloro-2-naphthylamine, like the corresponding bromine analogue, crystallises from benzene in golden-yellow needles; it melts at 133-134°. 0.1496 gave 0.0727 AgCl. Cl = 12.00. C19H1NCI requires Cl = 12.17 per cent. 14 The hydrocyanide crystallises from methyl alcobol in lustrous, colourless leaflets, and melts at 155-156°. 0.1263 gave 100 c.c. moist nitrogen at 15° and 744 mm. N = 9.07. C20H15N2Cl requires N=8.79 per cent. p-Hydroxybenzylidene-1-chloro-2-naphthylamine is somewhat sparingly soluble in organic solvents other than chloroform; it crystallises in pale yellow, nacreous leaflets melting at 191°. The hydrocyanide crystallises from benzene in colourless, rhombic plates, and melts at 151-152°. p-Methoxybenzylidene-1-chloro-2-naphthylamine crystallises from benzene in yellow leaflets and melts at 116-117°. The hydrocyanide forms well-defined, semi-opaque, white needles which gradually become tinged with green; it melts at 132°. 0.1378 gave 10 c.c. moist nitrogen at 16° and 766 mm. N=8.52. C19H15ONCI requires N=8.68 per cent. o-Hydroxybenzylidene-1-chloro-2-naphthylamine closely resembles the corresponding bromo-derivative, crystallising from benzene in orange leaflets, and from alcohol in large, orange, tabular prisms; it melts at 152-153°. Its hydrocyanide forms white, nacreous leaflets; these darken at 140°, and melt at 148°. Anhydro-bases derived from Nitrobenzaldehyde. o-Nitrobenzylidene-1-bromo-2-naphthylamine is readily obtained by the general method of preparation, and is readily soluble in all the ordinary organic solvents excepting light petroleum. It crystallises from a mixture of benzene and light petroleum in transparent, golden-yellow needles, and melts at 137-138°. 0.1808 gave 0·0945 AgBr. Br=22.24. C17H1102N2Br requires Br=22·53 per cent. p-Nitrobenzylidene-1-bromo-2-naphthylamine resembles its o-isomeride, and melts at 154-155°. o-Nitrobenzylidene-1-chloro-2-naphthylamine crystallises in goldenyellow needles and melts at 142°. 0.1730 gave 0.0782 AgCl. Cl=11·17. C17H1102N2CI requires Cl=11·43 per cent. p-Nitrobenzylidene-1-chloro-2-naphthylamine forms transparent, goldenyellow plates, and melts at 151°. These four anhydro-bases containing nitro-groups do not react with hydrogen cyanide. When excess of hydrogen cyanide is added to a dry ethereal solution containing 1-bromo-2-naphthylamine, and the mixture treated with p-nitrobenzaldehyde, also dissolved in ether, a yellow precipitate is produced consisting of the anhydro-base; the filtrate, after several days, yields a further quantity of this compound, but no trace of hydrocyanide. ROYAL COLLEGE OF SCIENCE, LONDON, CXV.-Action of Hydrogen Peroxide on Carbohydrates in the Presence of Ferrous Salts. 11. By ROBERT SELBY MORRELL, M.A., Ph.D., and JAMES MURRAY CROFTS, M.A., B.Sc. In a former paper (Trans., 1899, 75, 787), it was shown that hydrogen peroxide, in the presence of small quantities of ferrous sulphate, oxidises carbohydrates to osones. Oxidation by means of hydrogen peroxide in the presence of ferrous salts was first investigated by Fenton (Trans., 1894, 65, 899), and he has since examined its action on many polyhydric alcohols and hydroxy-acids (compare Trans., 1899, 75, 1; 1900, 77, 69, &c.). The osones were detected as products of the oxidation of the carbohydrates by hydrogen peroxide by precipitating them as osazones by phenylhydrazine at the ordinary temperature, but it has been found advisable to remove the osone from the solution as the lead hydroxide compound (Fischer, Ber., 1889, 22, 87). When baryta is added to a solution of an osone in the presence of basic-lead acetate, the lead hydroxide which is precipitated carries down all the osone with it. It is then quite easy to liberate the osone by means of dilute sulphuric acid, and to obtain a solution which reacts with hydrazines at the ordinary temperature and does not ferment with yeast. Glucose, lævulose, arabinose, and rhamnose have been oxidised by hydrogen peroxide in the presence of small quantities of ferrous sulphate, the osones removed from the solution by means of lead hydroxide and identified by means of their osazones. The osazones were always prepared by the action of phenylhydrazine at the ordinary temperature. In the case of arabinose, the solution was warmed to 60° so as to obtain the osazone precipitate in a more granular form, but this is allowable, since it has been shown that arabinose is more easily oxidised by hydrogen peroxide than glucose (Trans., 1899, 75, 792). Galactose seems to behave abnormally on oxidation. A red substance, very soluble in alcohol and ether, is precipitated by phenyl hydrazine at the ordinary temperature. Attempts to purify it have been unsuccessful. Most probably the oxidation of the galactose proceeds further than the osone stage, giving rise to products which are of an acid nature and react readily with phenylhydrazine. The stereochemical arrangement of the CH OH groups in galactose may be referred to as an explanation of the failure to detect galactosone; moreover, the identity of the osazone obtained from galactosone with galactosazone is uncertain (Fischer, Ber., 1889, 22, 96). Applying the method of oxidation by hydrogen peroxide in the presence of ferrous sulphate to cane sugar, it has been found that using neutralised hydrogen peroxide the carbohydrate is first 'inverted,' and the glucose and lævulose formed are then oxidised to glucosone. The action of potassium persulphate on glucose in the presence of ferrous sulphate is like that of hydrogen peroxide. The oxidation is very slow at the ordinary temperature, being most rapid at 40°. The yield of glucosone is much smaller than when hydrogen peroxide is the oxidising agent. The results of the action of bromine water on glucosone obtained from lævulose will be given in a subsequent paper. EXPERIMENTAL. Rhamnose. A 10 per cent. aqueous solution of rhamnose containing 0.6 per cent. of ferrous sulphate is oxidised by hydrogen peroxide in the usual manner. The rhamnosone is precipitated with lead hydroxide, and after removal of the lead by dilute sulphuric acid, sodium acetate is added in excess and then a solution of phenylhydrazine acetate. The weight of rhamnosazone precipitated at the ordinary temperature varies from 20 to 35 per cent. of the weight of the rhamnose taken. On recrystallisation from dilute alcohol, the rhamnosazone melted at 179-180° with decomposition. After drying in a vacuum, the substance was analysed. 0.1734 gave 0.4029 CO2 and 0·1061 H2O. C=63·36; H=6·7. 0.1875 26.8 c.c. moist nitrogen at 16° and 753 mm. N=16.5. C18H22O3N4 requires C=63·2; H=6·43; N=16·37 per cent. Cane Sugar. A 40 per cent. aqueous solution of cane sugar containing 0.2 per cent. of ferrous sulphate is oxidised by neutralised hydrogen peroxide in the usual manner. At first the action is slow and is accelerated by the addition of normal lead acetate after the first 1/10 atom of oxygen per molecule of cane sugar has been added. A quantity of hydrogen peroxide corresponding to 2 atoms of oxygen for a molecular weight of cane sugar is used. Basic lead acetate is added, the liquid filtered, the lead removed exactly by dilute sulphuric acid, and the glucosazone precipitated by phenylhydrazine at the ordinary temperature. The filtrate on warming to 50° gave a further quantity of glucosazone. The yield is about 30 per cent. of the weight of the cane sugar taken. The substance after recrystallising twice from absolute alcohol melted at 205° with decomposition and, after drying at 105°, gave on analysis the following numbers: 0.18 0.1892 gave 0·417 CO2 and 0·107 H2O. C=60·1; H=6·2. 24 c.c. moist nitrogen at 14.5° and 752 mm. N=15.5. C18H22O4N4 requires C=60·3; H=6·1; N=15.6 per cent. Action of Potassium Persulphate on Glucose. A 10 per cent. aqueous solution of glucose containing 0.8 per cent. of ferrous sulphate is treated with a quantity of solid potassium persulphate sufficient to provide one atom of active oxygen per grammolecule of sugar. The solution is warmed at 40° until the ferric iron formed begins to be reduced to the ferrous state; it is then allowed to stand at the ordinary temperature for some hours and afterwards treated with basic lead acetate, filtered, the lead removed from the filtrate by sulphuric acid, and the glucosazone precipitated at the ordinary temperature on addition of phenylhydrazine acetate. The yield of the osazone is 6 grams from 25 grams of glucose. On recrystallisation from alcohol, the melting point was found to be 205°, and a nitrogen determination in a specimen dried at 100° gave the following numbers: 0.1725 gave 23 c.c. moist nitrogen at 15° and 760 mm. C18H22O4N4 requires N = 15.6 per cent. N = 15.35. The authors wish to state that this research was carried out with the aid of a grant from the Chemical Society Research Fund and that they are indebted to Mr. F. M. Oldham for assistance in the experimental work. GONVILLE AND CAIUS COLLEGE LABORATORY, CAMBRIDGE. VOL. LXXVII. 4 0 |