.lpril 5, 1938
UROMOTRICHLOROMETIIANEAND CHLORO~LEFINS [ C O X r R I B G T I O N FRON THE
DEPARTMENT OF CHEMISTRY
1711
O F THE USIVERSITY OF FLORIDA]
The Preparation and Fluorination of Addition Products of Bromotrichloromethane and Bromo- and Chloro6lebs1 BY PAULTARRANT, MARYLOUISEBREYAND BENJAMIN E. GRAY RECEIVED SOVEMBER 14, 1957 Broiriotrichlorometharie has been found to react with a number of haloolefins to give simple addition products. The addition proceeds readily in the cases studied except whenever the halogen atoms are located both on a carbon atom having a double bond and on the carbon atom adjacent to it Fluorinations of some of the adducts have been carried out.
The peroxide-induced addition of bromotrichlo- The 2-trifluoromethylpropane adduct gave CFaromethane to olefins having a terminal double bond CHpC(CF3)BrCH3 and CF2C1CH2C(CF3)BrCH3 has been shown by Kharasch and c o - w o r k e r ~ ~which ~ ~ was converted to CF2=CH-C(CF3) =CH2. Since the preferred method of attack of a trito proceed as chloromethyl radical is on the terminal methylCH2=CHR + CC13Br + CClaCHzCHBrR The high yields of one-to-one addition products ob- ene group of a 1-alkene and the cases shown above tained from bromotrichloromethane and olefins indicate no abnormal effect due to chlorine or triseemed to warrant an investigation of the reaction fluoromethyl group, the additions to CHz=CBrof the bromide with haloolefins as a general means CH3 and CH2=CBrCH2C1 were assumed to give of preparing substances containing the trichloro- the straight-chain compound. The addition compound with 1-chloropropene methyl group which might be converted to various fluorine compounds. Since the preparation of also was found to be the straight-chain compound fluorobutanes was desired, this study was limited CCI3CHC1CHBrCH3as i t reacted with zinc to give to the reaction of bromotrichloromethane with an olefin. The isomeric CC13CH(CHa)C,HClBr chloro- or bromoolefins which would give a butane would not be expected to react with zinc to give an unsaturated compound. The properties of the deor isopentane derivative. halogenated adduct, CC13CH=CHCH3, are in Of twelve haloolefins treated with bromotrichloromethane in the present study, nine formed simple reasonable agreement, except for the refractive inaddition products. The properties of the adducts dex, with the values of CC13CH=CHCH3 reported are shown in Table I. Perfluoroallyl chloride, 1,l- in the patent literature.6 It is somewhat surprising dichloropropene and 1,2-dibromo-3-chloropropene that 1-chloropropene gave a yield of addition product twice as great as that obtained from 2-chlorofailed to form addition products. Kharasch and his colleagues established the propene. The structure of the addition product of 2-chlorostructures of a number of addition products of bromotrichloromethane and hydrocarbon olefins by 2-butene and bromotrichloromethane is believed to be CCl3CH(CH3)CClBrCH3 on the basis of its hydrolysis to known unsaturated acids. fluorination to a pentafluoroisopentane. The al%02 ternate compound CCI3C(CH3)ClCHBrCH3would RCI-I=CH2 + CCl$r ---+ not be expected to exchange its halogen atoms for X U ~ O C ~ I - IH ~ H RCHBrCH2CCl3 RC=CCOOH fluorine to give a pentafluoride as such replacements In the present study numerous attempts were normally occur only with carbon atoms containing made to obtain unsaturated P-haloacids by the use only halogen atoms.' The structure of the adduct from 1,3-dichloro-2of this procedure, but no acids were isolated. Consequently, different methods were used for the proof butene was not established as i t was obtained in a small yield. The addition to the symmetrical 1,4of structure of the addition products. Four of the olefins which reacted with bromotri- dichloro-2-butene leads to a single addition product. Kharasch has shown that allyl chloride reacts chloromethane had the structure CH2=CX- where X is chlorine, bromine or the trifluoromethyl group. readily with bromotrichloromethane to give 3T h a t these substituents had noeffecton the direction bromo- 1,1,1,4-tetrachlorobutanethus demonstratof addition across the double bond is indicated by ing that an allylic chlorine atom alone will not prethe compounds obtained by the fluorinations of the vent the addition from occurring. Recent evi2-chloro- and 2-trifluoromethylpropene adducts. dence8--'0 has indicated that bromotrichloromethThe former led to the known4 l-chloro-l,1,3,3-tetra- ane gives good yields of adduct with chlorotrifluorofluorobutane and to CF2ClCH2CFClCH,which was ethane from which it may be inferred that the trifluorovinyl group is capable of reaction with the dehydrochlorinated to 1,1,3-trifl~orobutadiene.~ methane derivative. It therefore seems logical to (1) This research was supported under Contract DA44-109-QMI4fi9 between t h e Oflice of the Quartermaster General a n d the Unipostulate, in the case of CF2=CFCF2C1, that the versity of Florida with Dr. J . C. RIontermoso a s t h e Project Officer. unreactivity toward bromotrichloromethane is not Presented in p a r t a t the 130th Meeting of the Smerican Chemical Society, Atlantic City, N . I., September, 1556. ( 2 ) M. S. Kharasch, 0. Reinmuth and W. H. Urry, THISJ O U R N A L , 69, 1105 (1947). (3) M . S. Kharasch and hl. Sage, J . Oyg. Chci?i., 14, 537 ( 1 W Y ) . (4) E. T. RlcBee and W. R. Hausch, I n d . Eng. C h e m . , 39, 415 ( I Y 47). (5) P. T a r r a n t , 4 . M. Lovelace and M. 12. Lilyquist, Tmrs J U L R N A L . , 77, 2783 (11338).
(GI E. C. Ladd and S. D. Shinkle, U. S . Patent 2,501,516 (1951). ( 7 ) P. Tarrant, M . R. Lilyquist and J . A . Attaway, THISJ o a R l r A L , 7 6 , 944 (1954). (8) A. 1,. Henne and D. W. Kraus, ibid., 73, 1791 (1951). (9) W. T. Miller, Jr., and J . M . Howald, Abstracts of Papers 122nd Meeting, American Chemical Society, Atlantic City, N . J., SFptember, 1952, p. 12-k. (10) K . S . Haszeldine and U. I
