NOTES
April, 1940 The Preparation of unsym-Difluorotetrachloro-
993
of this kind seems to have been prepared since except a zinc chloride addition compound of the hexamethyl ether of phloroglucin-phthalein.2 It is BY WILLIAM T. MILLER surprising that these compounds are all colored, No very convenient methods for the prepara- although the organic component might be colortion of unsym-difluorotetrachloroethane have less or even, as, e. g., in the case of dimethoxyappeared in the literature, although it has been phenolphthalein, incapable of assuming a quinosynthesized by the chlorination of diiluorotri- noid structure. chloroethane [CHClL!FGl] . l In this work, it By extending the Meyer and Hantzsch method was found possible to obtain the desired com- to other phthaleins we found a number of defipound satisfactorily from trifluorotrichloroethane2 nite typgs of addition compounds. As metallic [CF2C1-CC12F] and aluminum chloride. The salts we used stannic chloride and antimony pensimplicity of the experimental procedure and tachloride. Besides phenolphthalein and its dicheapness of the starting materials make the methyl ether, the phthaleins we dealt with were product readily available for the f i s t time. 3,6-dimethylfluoran, fluorescein and the lactoid This reaction is not entirely a simple replace- dimethyl ether of fluorescein. All addition comment of fluorine by chlorine as some gaseous prod- pounds we obtained were colored. It may be ucts are formed3 and too long heating leads to pointed out that all phthaleins mentioned above the formation of hexachloroethane. It was give colored addition products with acids also and probably for this last reason that Henne and that there is a certain connection between those Newman4 obtained little of the difluoro compound two series of addition compounds. after refluxing trifluorotrichloroethane with alumiThe substances were prepared by mixing the num chloride for forty-eight hours. component solutions in the manner adopted by Meyer and Hantzsch, a deep tint indicating the Experimental Two hundred cc. of trifluorotrichloroethane* and 40 g. formation of an addition compound. I n several of finely powdered aluminum chloride were refluxed on a cases the metal chloride was added without solsteam-bath for five hours. The surface of the aluminum vent, or cooling was necessary. If the resulting chloride turned dark during this period. Distillation of the product through a 50 X 1 cm. column packed with substance did not separate by itself, it was precipitated by a second liquid. glass helices yielded 51 g. of unsym-dauorotetrachloroThe substances formed differed widely in their ethane, b. p. 90-91 m. p. 40-41 and a very small residue composed principally of hexachloroethane. The lower stability toward water. Those derived from diboiling material distilled almost entirely below 48 but methylfluoran were the most stable. Some of was shown by freezing to contain appreciable amounts of CF2ClCCls. Longer periods of reaction yielded increased them were, because of their extreme sensitivity to moisture, obtainable only in a closed apparatus. quantities of hexachloroethane. A few substances were so unstable that they could (1) Locke, Brode and Henne, THISJOURNAL, 66, 1726 (1934). not be weighed for testing and the analysis had to (2) “Freon 113” of Kinetic Chemicals, Inc., Carney’s Point, N. J. (3) Compare U. S. Patent 1,994,035(C. A , , 29, 2974 (1935)). be limited to the determination of the proportion (4) H e m e and Newman, THIS JOURNAL, 60, 1697 (1938). of some constituents. In such cases the addition DEPARTMENT OF CHEMISTRY of indifferent molecules of the solvent could not be CORNELL UNIVERSITY ITHACA, N. Y. RECEIVED FEBRUARY 19, 1940 controlled. The compounds we prepared are collected in Table I. The compounds prepared by Meyer and Some Addition Compounds of Phthaleins and Hantzsch from the same components are inserted Metallic Salts* and denoted by “M. and H.” BY GEORGSACHS AND LILIRYFFEL-NEUMANN The compound (4) mentioned by Meyer and K. H. Meyer and A. Hantzsch in 1907l de- Hantzsch could not be obtained. Instead comscribed some compounds produced by addition of pound ( 5 ) resulted, but, whereas Meyer and metallic salts to phenolphthalein, its lactoid Hantzsch claim that the substance was formed dimethyl ether and its quinonoid dimethyl ether slowly, ( 5 ) precipitated at once. ester in non-aqueous solvents. No compound Except substance (9) which has a more com(*) Contribution ’from the 2nd:Chemical Institute of the Univerplicated farmula and substance (11) which is a salt sity of Vienna.
ethane
O,
O,
O
(1) K. H. Meyer and A. Hantzsch, &Y.,
40, a479 (1907).
(2) H.L a d , Chem. ZetZtr. 102, 11, 2696 (1981).
