Gen. Fayin THE CHEMICAL VOLUME CXXV. NEWS. EDITED BY JAMES H. GARDINER, F. Inst. P., F.C.S. No. 3248.-JULY 14, 1922. THE CHEMICAL NEWS, VOL. CXXV., No. 3248 Judgment has been given by the Referee in Arbitrations relating to the following complaints under the above Sub-Section. In accordance with the Award, "Acid Boric" is removed from the lists of articles chargeable with duty under Part I. of the Act as from 29th June:— Nature of Complaint. 1. That "Acid Boric" is improperly. included in the lists of dutiable articles. 2. That Re-agent Bottles, Hydrometer Jars, Museum Jars, Specimen Jars, Surgical Jars, Cylindrical Measures (bellshaped) and Conical Measures, are improperly included in the lists of dutiable articles. Judgment. 1. That Acid Boric " be removed from the lists. 2. Text of Award given below. THE REFEREE'S AWARD. In my opinion the question whether the descriptions complained of are properly included in the list of dutiable articles depends upon the meaning of the words used. I am satisfied that all the descriptions complained of are properly included in the list provided that these descriptions are used strictly and within the limits which are defined in this award. Re-agent bottles are properly in the list provided that by the expression re-agent bottle is meant a bottle which is reasonably fit for containing chemical re-agents. The legal obligation implied on the sale of such bottles is that the bottle shall be reasonably fit for containing any ordinary chemical re-agent, not fit for just a few but fit for any chemical reagent except possibly some exceptional substance calling for special and exceptional qualities in its container. This obligation means that the botle must be made of hard suitable glass free from lead. By "free" I mean containing no more than such a trace as does not matter. The neck and stopper must be ground so as to make a perfectly air-tight joint. If a bottle does not fulfil these requirements, it is not suitable for containing chemical re-agents, and is not scientific glassware. I gather that the distinctive shapes of re-agent bottles have been copied and that the description has been applied to inferior bottles, and that these practices have led to trouble with the Customs. That trouble is not for m eto deal with. A hydrometer jar means a jar suitable for hydrometer tests. It is of distinctive type, straight sided, of circular or elliptical section from 6 inches to 10 inches high. The glass must be good and very clear. The jar must be a very good cylinder and must be capable of standing rapid changes of temperature. Cylindrical Measures (Bell-Shape) and I think that these measures are on the border line, and that the only articles of these descriptions which can properly be considered as scientific glassware are measures which are in fact graduated with scientific accuracy. It is the correct graduation which, according to the evidence, makes them scientific glassware. I award that the descriptions complained of are properly included in the list if and when defined within the limits I have laid down. The complaint therefore fails. (Signed) CYRIL ATKINSON. [From the Board of Trade Journal, June 29th, 1922, page 719.] DEHYDROTHIOTOLUIDIN: ITS ISOMERS, HOMOLOGUES, ANALOGUES, AND DERIVATIVES. BY MARTIN MEYER, B.Sc., M.A. NEW YORK CITY. (Continued from Last Week). 2. The Kalle Method. The It was observed that the relative amount of napthalene as required in the Casella Method could be varied greatly, without affecting the yield. (In order to determine whether there was compound formation between the napthalene and the other substances in the melt, a cooling curve was taken, which indicated that there was not, as may be seen from the diagram.) napthalene was then omitted entirely, the fusion being carried out as directed in the Kalle patent, but extraction was still used for purification, and the yields and results. were the same as those just described. It was therefore concluded that the claim that the use of napthalene increases the yield is unfounded, its only advantage being as temperature regulator. The method of purification by vacuum distillation was next tried in a preliminary way. For this purpose melts prepared by the Kalle method as well as samples of the crude material made similarly by the DuPont Co., were used. These melts distilled around 345° C. at a pressure of 35 mm. and yielded a product which on a single crystallisation from alcohol appeared in very pale yellow, odourless needles, which on further recrystallisation from ethyl alcohol were finally obtained at a constant melting point of 194.8° C. (cor.). This was undoubtedly pure and probably the purest sample of the compound which has been prepared up to this time. The procedure is a difficult one to carry out, the yeilds here were less than 20 per cent. of the weight of the starting material, and the distillation was panied by much foaming and decomposition, the greater part of the starting material remaining in the flask as coke at the As this was, however, finally conend. cluded to be the only feasible method of purification, the complete details will be given later. accom 3. Attempt to Develop a New Synthesis of Dehydrothiotoluidin. The work done on the compound up to this point led to the conclusion that in order to prepare a quantity of the substance sufficient for further investigation, and in a satisfactory state of purity, a new synthesis would be highly desirable. The criteria for this reaction as a laboratory problem are: (a) Simplicity of mechanical operations. (b) Large yield. (c) Avoidance of the formation of primulin which prevents the satisfactory crystallisation of the compound without introducing large quantities of other by-products. (d) Availability of starting materials. From consideration of the general methods by which thiazoles have been prepared, the following proposed syntheses are obvious at once : (a) Condensation of para-amino-metathiocresol with para-amino-benzoyl chloride. (b) Fusion of of para-amino-benz-paratoluidid with sulphur. (c) Oxidation of thio-para-amino-benzpara-toluidid with potassium ferricyanide. (d) Fusion of paranitro-benzal-paratoluidin with sulphur analagously to the patent method for preparing "Rosenkörper. 75 It was hoped that in this reaction, if it occurred at all, the hydrogen sulphide formed would reduce the nitro group to the amine, otherwise a final reduction would be necessary. This method was chosen as the easiest to perform because it is readily seen that the required Schiff's base should be easily obtained by condensation of paratoluidin and paranitrobenzaldehyde. This expectation was justified and the compound was prepared just before the publication of the article by Lowy and King" on the condensation products of paranitrobenzaldehyde which it is described. in 4. Para Nitro Benzal Paratoluidin. Large quantities of chromyl chloride were. prepared by the method of Law and Perkin, and paranitrobenzaldehyde by that of V. V. Richter. 76 Molecular quantities of the two substances, paratoluidin and paranitrobenzaldehyde, are dissolved separately in the least amounts of 95 per cent. ethyl alcohol and refluxed for one hour after mixing. The solution is evaporated to a small volume, allowed to crystallise, and the product filtered off and recrystallised from ethyl alcohol. Paranitrobenzal-paratoluidin appears in pale yellow needles melting at 123° C. (cor.). The yield is only about 50 per cent. of the theoretical in a pure state as it is very soluble in alcohol and the losses during crystallisation are large. 5. Fusion of Paranitro-Benzal-Paratoluidide with Sulphur. It was expected that on fusion with sulphur this compound would behave in one of two ways, or perhaps, both, as follows: Accordingly 16 g. of the Schiff base and 4 g. of powdered roll sulphur were mixed intimately and used on an oil bath in a flask equipped with a reflux condenser for 14 hours at 200° C. Vigorous ebullition occurred almost at once, and sulphur dioxide was evolved rapidly. The mass became viscous at the end of three-quarters of an hour and was almost entirely solid at the end of one hour. Allowed to cool, broke the flask and pulverised the melt, which was black in colour and weighed 16 g. It was then extracted twice with concentrated hydrochloric acid in 100 cc. portions which were diluted with water, neutralised with sodium hydroxide and filtered. The acid solution changed from yellow to a milky purple at the neutral point. A small amount of purplish-brown material, the dry weight of which was less than 1 g. was obtained. The mass appeared to have charred to a large extent and the yield was too small to proceed further with. It was not dehydrothiotoluidin or the nitro compound, and resembled the product obtained later from nitrotoluene in every way. It was thought that a lower temperature might improve the results, so the experiment was repeated, using xylenes as a diluent and temperature regulator. A mixture of 12 g. of paranitro-benzalparatoluidin, 55 cc. of xylenes, and 3 g. of sulphur, was refluxed for 5 hours, the mixture was then diluted with water and steam distilled, and the xylene recovered from the distillate. The residue in the flask consisted of a dark brown solid and a yellow substance, more of which is deposited in yellow needles from the water solution on cooling. Filtered and separated the yellow needles from the brown material which was present in large lumps. None of the starting material was obtained from this, although the brown mass did contain free sulphur. The products of the reaction were the brown, −NO2+ 25 = €‚„H12N2S+SO2 amorphous, insoluble material, and the yel 14 low crystals, which are soluble in alcohol from which they crystallise in small crystals -NO2+25=C„H1N2SO̟2+ H2S of indistinguishable shape, melting at 227 10 resulting either in the formation of dehydrothiotoluidin or the corresponding nitro derivative. 73. D. R. P., 51, 172; Friedländer, Vol. 2. 74. Lowy and King, J. A. C. S., 43, 627 75. Law and Perkin, J. C. S., 91, 191 (1907). 76. V. V. Richter, Berichte, 19, 106 (1886). 228° C. (cor.). The water solution of this compound is acid to litmus, qualitative analysis showed the presence of carbon, hydrogen, and nitrogen, and a sample gave the reduction test for the nitro group. It was not investigated further as it was evidently not the desired sulphur base. 6. Fusion of Paranitrotoluene and Sulphur. At this point the thought suggested itself that paranitrotoluene should yield dehydro A mixture of 30 g. of paranitrotoluene and 15 g. of sulphur was heated under a reflux condenser and for two hours sulphur dioxide was evolved vigorously. The melt, which on cooling weighed 29 g., was powdered and extracted three times with 100 cc. portion of concentrated hydrochloric acid which were then drowned in ten times their volume of water. On standing a dark brown flocculent precipitate settled out, and was filtered off and dried. It blackened up somewhat on standing, and weighed 7 g. when dry. The extract was pulverised and warmed with 100 cc. of ethyl alcohol, filtered, and the deep red solution was evaporated down and allowed to crystallise, yielding about a gram of light brown microcrystals that appeared to sublime or decompose around 220° C. Qualitative analysis showed the presence of carbon, hydrogen, nitrogen, and sulphur. Zinc dust in 50 per cent. ethyl alcohol appears to react with the substance as it gives a yellow solution with a pale green fluorescence, but the reaction mixture does not reduce ammoniacal silver nitrate and consequently the original substance is not a nitro compound. Gatterman and Neuberg" prepared dehydrothiotoluidin from thio-paranitro-benztoluid by the Jacobson reaction. They describe the nitro compound as crystallising in yellow-red needles from glacial acetic acid, and none of the above mentioned substances resembles, even slightly, this or dehydrothiotoluidin. The substance obtained in this reaction is a sulphur compound, probably identica! with that obtained from para-nitro-benzalparatoluidid, has some tinctorial value, and does not correspond to any that have been prepared. As it can be made easily in moderately large quantities, it might be worth while to investigate the reactions further, but as for the preparation of dehydrothiotoluidin, these experiments failed, this was not done. 77. Gatterman and Neuberg, Berichte, 25, 1081 (1892). |