hours; the amount of hydrogen chloride obtained was 0.207 gram, while the amount required by theory is 0.209 gram, supposing the reaction to take place as follows: CH,F+ Cl2 = CH2CIF + HCl. The methylene chlorofluoride seems to be more soluble in water than fluoride of methyl, but is easily expelled again when the aqueous solution is warmed. This property can be made use of in purifying the gas from traces of air. The sp. gr. of the gas was found to be 34.18, while the theoretical sp. gr. is 34 25. The gas is hardly inflammable, and considerable difficulty was experienced in exploding it with oxygen alone, the combustion only taking place when a powerful electric spark was passed through the mixture; when mixed, however, with hydrogen and oxygen, it explodes easily with an ordinary electric spark. Several analyses were made, with the following results : : III. Thus showing that the gas produced its own volume of carbon dioxide after combustion. An estimation of the chlorine was also made; 0.03526 gram gas gave 0.072 gram AgCl = 50·6 per cent. Cl. CI Found. Calculated for CH.CIF. 51.8 An attempt was made to estimate the fluorine, but the results were 3 per cent. too low. Methylene chlorofluoride seems to be much more easily decomposed by water than methyl fluoride, for if an aqueous solution of this gas be allowed to stand for two or three days, both hydrochloric and hydrofluoric acids can be detected in the water. Methylene chlorofluoride does not seem to react easily with chlorine, and the two gases when mixed in equal volumes and exposed to sunlight for many days, remain partly uncombined. I hope, however, to be able to continue the investigation. I may mention that experiments made to obtain tetrafluoride of carbon, by passing a mixture of fluoride of silicon and carbon dioxide through a platinum tube heated to bright redness, were not successful. Silica was certainly formed in the platinum tube, and traces of a liquid were obtained which might possibly have been tetrafluoride of carbon, but unfortunately only in such small quantities that no analysis could be made. During these experiments, when the mixture of carbon dioxide and silicon tetrafluoride was passed through a red-hot platinum tube, the following piece of apparatus was found to be extremely useful, and might doubtless be also used in many other experiments where the same result is desired. The object was to enable a continuous stream of the same gas to be slowly passed again and again through the red-hot platinum tube. A was connected with the platinum tube, beyond which was a balloon (with two stopcocks) containing the mixed gases. B was connected directly with the balloon. The tube C was made of the ordinary glass tubing, such as is used for the Sprengel pump. When the receiver D was filled with mercury and raised just high enough to allow the mercury to flow down the tube C, gas was carried down with the falling mercury into the wider tube E; here the mercury escaped into the basin F, while the gas was forced through B back again into the balloon, and was then ready to be used again. XVII.-Researches on the Constitution of Azo- and Diazo-derivatives. V. Compounds of the Naphthalene B-Series-continued. By RAPHAEL MELDOLA, F.R.S., and GILBERT T. MORGAN. In the last paper referring to the present branch of investigation (Trans., 1888, 460; Meldola and East), it was shown that the azoderivatives of B-naphthol contain an atom of hydrogen capable of being displaced by acid radicles, a property which they share in common with their a-analogues (Zincke and Bindewald, Ber., 1884, 3030). Of the alkyl-derivatives of the azo-B-naphthol compounds, the only representative at present known is the benzeneazo-ẞ-naphthyl ether of Weinberg (Ber., 1887, 3171). The importance, from a theoretical point of view, of ascertaining whether this displaceable hydrogenatom of the azo-3-naphthol compounds is attached to the oxygen or to the nitrogen of the azo-group has from time to time been pointed out in the course of the present series of researches, and has recently been emphasized in a paper read by one of the authors at the Bath meeting of the British Association (Phil. Mag., 1888, 403). The present paper contains the results of experiments undertaken with the object of throwing further light on this question. I. Benzoyl-derivatives of Azo-B-Naphthol Compounds. Acetyl-derivatives of azo-B-naphthol compounds can be prepared, as pointed out in the last paper, by two distinct methods. If the radicle attached to the azo-group is more or less of an acid character, such as nitrophenyl, CH, NO2 (p or m), the corresponding B-naphthylamine azo-compound is attacked by nitrous acid in the presence of glacial acetic acid, with the formation of the azo-naphthyl acetate (loc. cit., p. 465).* This method does not appear to be applicable * The formation of phenylic acetates from the corresponding amines, by means of the diazo-reaction in the presence of glacial acetic acid, was made known in a paper communicated to the Chemical Society of Germany on January 24th, 1888 (Ber., 1888, 601), and in a subsequent paper read to this Society (Trans., May, 1888, 465), it was stated that "as the reaction promises to be widely applicable for the synthesis of phenylic acetates and other ethereal salts, it is proposed to extend the investigation in this direction, and to make a special study of the conditions which determine the displacement of amidogen by the C2H2O-O-group by means of the diazo-reaction." Notwithstanding the publicity thus given to the method, and the explicit claim to continue its further investigation, a paper appeared in the Amer. Chem. Jour. of last September (10, 368) by W. R. Orndorff, containing the results of the application of this reaction for the formation of phenyl, cresyl, and when the radicle attached to the azo-group is not acid, such as phenyl or naphthyl, CH, C10H7, &c., in the azo-ẞ-naphthylamine compounds. In such cases, however, azo-ß-naphthyl acetates can be prepared by the direct acetylation of the azo-ẞ-naphthol compounds by means of sodium acetate and acetic anhydride, and the same method is generally applicable, whatever may be the nature of the radicle associated with the azo-group. The same remarks apply to the benzoyl-derivatives of azo-p-naphthol compounds, some of which have been prepared by both methods in the manner described below. Benzeneazo-B-Naphthyl Benzoate, CH, N2 C10H OC,H2O(ß). This compound cannot be prepared by fusing benzeneazo-3-naphthylamine with excess of benzoic acid, and adding the calculated quantity of sodium nitrite to the mixture: complete decomposition takes place under these circumstances with the formation of tarry products. A mixture of benzeneazo-ẞ-naphthol with dry sodium benzoate and benzoic anhydride, if heated for some hours to the fusing point of the anhydride, gives only a small yield of the azo-ẞ-naphthyl benzoate, owing to the difficulty of keeping the mixture in a homogeneous fluid condition, and to the continuous loss of anhydride by sublimation. After many partially successful attempts with benzoyl chloride, the following method was found to give perfectly satisfactory results :: Benzeneazo-ẞ-naphthol is mixed with about an equal weight of dry and finely powdered sodium benzoate, and the mixture is then made just pasty with benzoyl chloride. The flask containing the mixture is fitted with a cork perforated for the reception of a tube drawn out to a fine point, and heat is applied by immersing the flask in boiling water.* The reaction commences immediately on the application of heat, and is complete in about an hour, when the product is repeatedly extracted with hot water as long as benzoic acid is dissolved out. The contents of the flask fuse to a dark reddish oil under boiling water, a property which facilitates the washing operations, as the oil and hot water can be thoroughly mixed by agitation, and the former rapidly subsides to the bottom of the flask on allowing the contents to remain at rest for a few minutes. The benzoyl-derivative is easily decomposed by other acetates from aniline, toluidine, &c. The investigation of the method has been going on in my laboratory since the beginning of last year, and these and other acetates and benzoates had been prepared from the diazo-salts of the corre sponding amines before the appearance of the paper by the author referred to. ---R. M. * At higher temperatures the reaction takes a different course; tarry products are formed which have not been further investigated. ammonia, even when the latter is very dilute, so that it is unsafe to attempt to shorten the washing by the use of ammonia. In some of our first preparations, unaltered benzeneazo-B-naphthol was always found, and this was afterwards traced to the use of ammonia in the washing waters. Sodium or ammonium carbonate also readily hydrolyse the benzoyl-derivative, and it is evident that the benzoyl-group is much more readily removed from this compound than is the acetyl from benzeneazo-ẞ-naphthyl acetate. When completely washed, the substance is crystallised from boiling alcohol, in which it dissolves readily. A specimen was further purified for analysis by dissolving in chloroform, in which it freely dissolves in the cold, and allowing the solvent to evaporate spontaneously in an open dish. The substance forms dense, orange-red crystals melting at 125°. 0.1025 gram gave 0·2951 gram CO2 and 0·0438 gram H2O. 0.0894 gram burnt in a vacuum with CuO gave 5'9 c.c. moist N at 13° C., and 770-1 mm. bar. Metanitrobenzeneazo-ß-naphthylamine (m. p. 182°) is fused with excess of benzoic acid, and the calculated quantity of dry sodium nitrite added in small portions to the fused mixture. Nitrogen is freely given off, and when all the nitrite has been added, the product is washed with hot water till free from benzoic acid. The washing may in this case be accelerated by the use of dilute ammonia without fear of decomposition. The washed product is crystallised from hot glacial acetic acid, in which it is not very soluble, and finally from boiling alcohol, in which it dissolves only very sparingly, separating on cooling in the form of dull, reddish-orange, silky needles. The melting point is 171°. The following results were obtained on analysis : 0.1676 gram gave 0-4280 gram CO2 and 0.0612 gram H2O 0.2196 gram burnt in a vacuum with CuO gave 19-8 c.c. moist N at 17° C. and 761.7 mm. bar. |
