EASTERFIELD : PHEXYLBROJXACETIC ACID. IX.-Pl~enylbromacetic Acid, an appayent Exception to the Le Bel- Van’t I€(# Hypothesis. By T. H. EASTERFIELD. VAN’T HOFF, in his “Dix Annhes dens 1’Histoire d’une Thkorie,” after referring to the reservations which accompanied the introduction of his fundamental idea, expresses his views in the following sentence (‘i Dix Annkes,” p. 49) :-‘‘ Or depuis lors la dkcouverte de l’act.ivit6 chee l’iodure de l’alcool amyl secondaire CHI*CH3mC3H7, par M. le Bel, a prouvk que mhme la ditI6rence entre l’hydroghe et un atome haloghe suffit A la production du pouvoir rotatoire ; depuis lors il parait que toute restriction a perdu sa raison d’ktre.” Up to the present time, however, this amyl iodide of le Be1 appears to stand alone as the only active compound in which we have reason to bclieve that a halogen is united to the asymmetrical carbon.It therefore seemed desirable that similarly constituted haloid deriva,. tives should be prepared and studied. Accordingly, at the Yuggestion of Professor Emil E’ischer, I have attempted to prepare other active substances of the type alluded to, and although the results obtained so far are only of a negative character, they may perhaps possess sufficient interest to excuse their presentation before the Society.76 EASTERPIELD : PHENTLBROJIACETIC ACID. Active mcndelic acid was chosen as the parent substance ; it was prepared from amygdalin according to the directions given by Lewkowitsch (Bey., 16, 1565) ; 1 gram of the acid was sealed up in ;I tube with 10 to 15 times its weight of fuming bpdrobromic acitl saturated a t 0".The mandelic acid rapidly dissolved, yielding a 'clear solution. The tube was now placed in a water-bath a t 50' and maintained a t that temperature for two hours ; a t the end of that tlime *the rniandelic acid had becouie transfoi*med into phenylbromacetic; acid, C,H,-CHBr.COOH, most of which had separated as a light brown oil ; this solidified on cooling, and after recrystallisation from boiling light petroleum showed a melting point of 7E?-80°. Tho alcoholic solution of the brominnted acid was absolutely inactive ; the melting point of the acid corrcsporids with that of the infictive brominated acid prepared from inactive mandelic acid by the same process. On gently warming the acid with dilute soda soluti(8n, acidifying, and extracting with ether, it yielded inactive mandelic acid melting a t 118".&ni1ai*ly, plienj-lchloracetic acid, prepared by the action of hydro. chloric acid on active mandelic acid, was found t o be inactive and to correspond in melting point and general character with the inactive synthetical acid. With fuming hydrochloric acid, however, a tempera- ture of 95--100" was necessary in order to start the reaction. It was not found possible to prepare an active chlorinated acid by the action of phosphorus pentachloride on an ethereal solution of actire mnridelic acid. Fuming hydriodic acid appears to have no action c n niaiidelic acid a t low temperatures ; at the temperature of the laboratory in sunimw, reduction took place gradually, no iodcr-acid being formed.The resoliltion of the halogenated acids by means of the alkaloid salts was also attempted but without success; the chlorinated and brominated acids are slowly decomposed even by cold water, and the alkaloids a t once remove the halogen atom. The difficulty of finding a suitable solvent prevents these substances being submitted t o the action of organised ferments. These remarks apply equally to bromosuccinic acid, with which some experiments were tried. Kekul6 (Awnalen, 130, 21) has prepared! bromosuccinic acid by the long-continued actiou of hydrobrornic acid on active malic acid a t 100". Here again the brominated acid -as inactive, and yielded inactive rrialic acid on treatment with moist silver oxide. Kekule remarks that it would have been oiily reasonable to expect an active brominated derivative to have been formed under these circum- stances, and surely the same remark holds good in the case of the reautiou between hydrobromic and active mandelic acids a t so low a temperature aa 50".In the case of malic acid, it may indeed beACTION OF HEAT ON NITROSTL CHLORIDE. 73 supposed t h a t malelic acid has been first formed, that this has been converted into fumaric acid, and has then taken up the elements of hydrobromic acid to form the inactive bromosuccinic acid ; such an assumption is impossible in the case of mnndelic acid. It would be indeed rash to generalise from the few facts before us, but the possibility certainly seems t o suggest itself that such strongly negative radicles as chlorine and bromine cannot be introduced by subst,itution into an asymmetrical active group without destroying the activity of the molecule. This might he due either to the fact that there is something in the nature of these atoms themselves which prevents activity in their compounds, or what is perhaps more likely, because the introduction of so chemically potent an atom produces such a disturbing effect on the whole molecule that a general re-arrangement of its atoms becomes necessary ; in other words, that intramolecular change takes place. The above investigation was carried out in the laboratory of the University of Wurzburg. I take this opportunit'y of expressing my deep indebtedness to Professor Fischer for the characteristic kindness which I have received at his hands.