Vol. 76
NOTES
1388
TABLE I PHYSICAL PROPERTIES OF THE CHLORINATEDFLUOROETHERS Compound
"C.
B.P., Mm.
d%
n*OD
MRa
.MRb
Chlorine. 40 Calcd Found
ARF
CICHzOCFzCFHCle 104.5 1.12 37.76 35.75 624 1.5269 1.3768 27.46 27.52 CHClzOCFzCFHCl 112.5 48.92 49.09 626 1.5620 1.3883 31.99 32.40 1.13 CClaOCFzCFHCl 131 629 1.6631 56.31 56.18 1.4090 36.85 37.39 1.17 CClSOCFzCFClz 142 626 1.7141 41.73 42.11 1.13 61.91 61.36 1.4187 CICHzCHz0CFzCFHClc 84 36.04 37.15 100 1.4620 1.3935 1.23 32.08 32.44 CH,CHCIOCFzCFHCIC 68 36.01 35.95 100 1.4020 1.3755 31.74 32.17 1.14 CHzClCHClOCFzCFHCl 97 4%5,95 3 6 , 0 7 100 1.5426 1.4080 36.61 37.02 1.13 CHC1~CHCIOCF~CFHClc 85 53.34 53.17 23 1.6438 1.4291 41.47 41.66 1.06 CC1~CC120CFzCFCl~ 94 07.25 67.02 10 1.7819 1.4575 56.07 56.00 0 973 CC12=CClOCFzCFClr 89 59.42 r,9.35 40 1.7054 1,4440 43.97 46.30 1.14 Calculated by adding the L omic increments. * Observed values, calculated by means of Lorer z-T,orctiz equntion. Also reported by Rapp, Barr, et al., THISJ O U R N A L , 74, 751 (1952). rinated ethers and subsequent treatment of the reaction mixture with cold concentrated ammonia produced dichlorofluoroacetamide melting at 123'. Preparation of CClZ=CCl-O-CF2CFC12.-To a mixture of 27 g . of powdered zinc in ethanol was added slowly 128 g. (0.37 mole) of CCl82ClrO-CF2CFC12 with efficient stirring. A vigorous reaction occurred with evolution of heat which was removed by cooling in an ice-bath. After the addition of ether was completed, the mixture was refluxed gently for one hour. The reaction mixture was then filtered to remove zinc chloride and the filtrate washed with water and dried. Fractionation gave 98 g. of CClz=CCl-O-CF~CFCl~ distillina a t 89" a t 40 mm. Dressure. This structure was assignex on the basis of analysis and molar refraction. Table I summarizes the physical properties of the various Chlorination products. In summary, it may'be stated that the initial chlorination of CHs-0-CFZCFCIH 'and CzHh-O-CF2CFCIH takes place exclusively in the alkyl portion of the ether with the hydrogen of the CFClH group being the last to be replaced by chlorine. DEPARTMENT OF CHEMISTRY USIVERSITYOF COLORADO BOULDER, COLORADO
The three N-bromo amides also were treated with cyclohexene which, like toluene, provides an TABLE I OF INFRARED ABSORPTION COEFFICIENT, OL, CORRELATION WITII BROMINATION STUDIES O N TOLUENE a
Ring hromination.%
S i d e chain
Compound
CFSCFaCOSHBr CFSCF2CF2CONHBr CF3CF2CF&F2COSHBr CF3COSHBr (for conipnrisoti )
178 200 246 250
AIL9 73.9 SR,7 88
301
;1 H
2, 1953 RECEIVED NOVEMBER
The preparation and brominating properties of some halogenated N-bromoacetamides have been previously described3 and the brominating activity of the N-Rr bond related to the infrared intensity of the N-€1 fundamental band at 2.93 p.4 I n this work, the Y-bromoperfluoramides CFsCF2CONHBr, CF&F?CF*CONHBr and CF&FzCFzCF2CONHBrwere prepared following the method previously d e ~ c r i b e d . These ~ three compounds were separately treated with toluene; the percentage side chain bromination was compared to the percentage ring bromination and the absorption coefficient, a, calculated for the N-H fundamental hand a t 2.93 p. Table I shmvs that the correlatim found between these two factors falls in line with those previously described. (1) This work was supported in p a r t b y a crant-in-aid from the hlinnesota Mining and hlanufacturing Co., St. Paul, Minn. (2) This paper represents in part work done at the IJniversit? of Colorado i n partial fulfillment o f t h e requirements for t h e 1'h.D. decree. (n) J . D. P a r k , J. R . Lacher, el ai..TIIISJouR.;.~I.,74, 2180 ( I Q . ? ? ) . ( 4 ) T . I?. r a c h r r , T. Park, e l n! . ibitl., 7 4 , 5578 (lQR?\.
tion,vp
sii
1 I:: :1
1
opportunity for bromination to occur by free radical and ionic bromine. Table I1 shows the results of this study. Along with allylic bromination and addition of bromine across the double bond, some adducts of the type A
Rr-C-N
Properties of Some Perfluorinated N-Bromo Amides' BY J . D. PARK,W.R. L Y C AAND ~ J. R. LACHER
hrornin:i-
where Rf = CF3CF2-, CF3CF2CF2- and CF3CF2CF~CFZ-,were isolated in each case. TABLE I1 BROMINATION STUDIES ON CYCLOHEXENE 1.2-
8-Bromocyclohexene, Compound
CF3CF2CONHBr CF3CF2CF2CONHBr CF3CF2CF2CF2COSHBr
72 17.2 11.5
0
Dibromocyclo-
hexane,
Adduct,
9.3 9.5 14
11.9 16.9
"0
(-7
11.6
It will be noted from Table I1 that the percentage of bromination resulting from homolytic cleavage of the N-Br bond decreases and that the total of the two products resulting from heterolytic cleavage of the N-Br bond increases in the same order as the absorption coefficients (Table I) increase. The 3-bromocyclohexene had a b.p. of 77-83' (35 mm.) and Y Z ~ O D 1.5279 (lit. 80' (35 mm.), Y Z ~ O D 1.5280). The 1,2-dibromocyclohexane had a b.p. of 100105' (15 mm.) and ~ Z ~ O D1.3534 (lit. 99-103' (10 mm.), a z n1.5532). ~ The properties of the various new compounds nrc
given in Table HI,
Mar. 5 , 1954
NOTES
1389
from ethylmagnesium bromide and methyl n-amyl ketone; lit.' b.p. 80-81" (13 b.p. 100-102" (30 mm.), n Z o1.4321; ~ Ethyl-n-butyl-n-amylcarbinol resulted inm.), n z o 1.4315. ~ Analyses, Yo from the condensation of n-amylmdgnesium bromide with Compound OC. Calcd. Found ethyl n-butyl ketone; b.p. 119-120' (20 mm.), n l b 1.4430; CFa(CF2)aCOOEt ...' F, 58.5 58.2 lit .e X ~ O D 1.4424. n-Butyl-n-hexyl-n-heptylcarbinol was prepared by treating n-butyl n-hexyl ketone with n-heptylCF~CF~CONHI 95-96 F, 58.3 58.3 magnesium bromide in the usual manner. The product CF3CF2CONHBr 69 Br, 30.03 29.84 was isolated in 66% yield, b.p. 157-159' (1 mm.), n"D 80 Br,27.37 27.43 CF~(CFZ)~CONHB~ 1.4520. CFS(CF~)~CONHB~ 87 Br.23.35 23.36 Anal. Calcd. for C I ~ H ~ ~C,O79.92; : H, 14.16. Found: o-BrC6HbNHCOCF?CFa 126 Br, 24.65 24.43 C, 79.90; H, 14.05. N, 4.35 4 . 3 2 Tertiary Bromides.-The bromides were prepared essentially by the procedure of Hakes as modified by Whitmore o-13rC6HbSHCOCF2CF2CF3 139 Br, 21.36 21 .On LVilliams' for tertiary chlorides. The tertiary alcohols s, 3.74 3 . 8 2 and were saturated with hydrogen bromide at ice-bath temperao-BrCtiH6SHCOCF2CF2CF1CF3 133 Br, 18.84 19.02 ture and the resulting bromides were separated from the 1v, 3 . m 3.29 water which had formed. Excess hydrogen bromide was removed on a water aspirator and the products were washed B.p. 110' (627 mm.), n z 01.3060. ~ with an equal volume of concentrated sulfuric acid. They DEPARTMENT OF CHEMISTRY were allowed to stand over anhydrous sodium carbonate and OF COLORADO UNIVERSITY sodium sulfate in a refrigerator for 12-15 hours. After reBOULDER, COLORADO moving the drying agents, the tertiary bromides resulted in yields of 70-80%. Since the bromides could not be distilled without decomposition, they were used without furUnsymmetrical Tetraalkylmethanes. I. Coupling ther purification. The following bromides were obtained in the above manner: ( a ) 5-ethyl-5-bromodecane, n20~ of Alkyhagnesium Bromides with 1.4650. Anal. Calcd. for ClrHzaBr: C, 57.82; H, 10.11. Tertiary Bromides' Found: C, 57.81; H, 10.20. ( b ) 3-Methyl-3-bromooctane, ~ * O D 1.4545. Anal. Calcd. BY NORMAN RABJOHN A N D M. J. L A T I N A ~ for CgHLBBr: C, 52.20; H , 9.25. Found: C, 52.28; H, 9.46. RECEIVED NOVEMBER 20, 1953 (c) 4-Ethyl-4-bromooctane, ~ * O D 1.4635. Anal. Calcd. The coupling reaction of Grignard reagents with for C1OH21Br: C, 54.30; H, 9.57. Found: C, 54.30; H , tertiary alkyl bromides was investigated as a 9.65. 7-Butyl-7-bromotetradecane could not be prepared by means of obtaining unsymmetrical tetraalkyl- this process since the corresponding carbinol solidified a t methaiies which contain a minimum of sixteen ice-bath temperature. Accordingly, hydrogen bromide was carbon atoms. A number of other investigators3s4 introduced into the carbinol a t room temperature! and the have employed this procedure, but have worked resulting product failed t o give satisfactory analytical data. Coupling of Grignard Reagents with the Tertiary Browith compounds of lower carbon content and mides.-The method of preparation of 6-ethyl-6-butylapparently have made only quaternary hydro- tetradecane is illustrative and similar t o that of Campbell carbons in which a t least two of the alkyl groups are and Eby.4 n-Octylmagnesium bromide was prepared from 24 g. (1 gram atom) of magnesium, 193 g. (1.0 mole) of nsimilar. octyl bromide and 500 ml. of anhydrous ether. The broWe have found, in agreement with others, that mide was added over a period of 2 hours and the reaction the coupling process is not clean-cut and the yields mixture was stirred for an additional hour. The ether was of the desired hydrocarbons are low. Two CI6- removed by distillation and the temperature of the reaction hydrocarbons were prepared in the present study mixture was raised to 140'; then 200 g. (0.8 mole) of 5was added within 2 hours. A white in yields of 10 and 1.5% and a Czo-hydrocarbon, ethyld-bromodecane slurry formed and stirring became difficult. The mixture ,5-ethyl-S-octyldecane, was obtained in 16% yield. was heated for 4 more hours and allowed to stand overnight. However, attempts to prepare a C24- and a C30- Water was added slowly with cooling and stirring, followed hydrocarbon by coupling n-dodecylmagnesium by 10% hydrochloric acid solution until all solids had disThe mixture was extracted several times with bromide with 5-ethyl-5-bromodecane and i-butyl- solved. ether and the combined extract was washed with water, 10% 7-bromotetradecane, respectively, failed. Treat- sodium bicarbonate solution, again with water and dried ment of 5-ethyl-5-bromodecane with n-propyl- over anhydrous sodium sulfate. The ether was removed by distillation and the residual oil was distilled from a lithium also led to negative results. Clark flask. The higher boiling fraction was purified The solidification points of the three unsym- through a medium bore Todd column to give 38 g. (16%) of metrical tetraalkylmethanes which were prepared a colorless liquid; b.p. 179-183' (18 mm.), n Z o 1.4480, ~ d204 0.799; M R calcd. 94.6, found 94.7. were found to be in the range of - 70 to - 7*j0. Anal. Calcd. for C20H42: C, 85.02; H, 14.98. Found: Experimentals C, 85.16; H, 14.86. Tertiary Alcohols.-These compounds were synthesized The sixteen-carbon hydrocarbon, 5-ethyl-5-propyldecane, in 40-6070 yields in the typical fashion from the appropriate was obtained by coupling n-hexylmagnesiurn bromide with Grignard reagents and ketones. Ethyl-n-propyl-n-butyl5-ethyl-5-bromooctane in the above manner. There was carbinol was obtained from the reaction of n-propylmagneisolated 39 g. (15%) of a colorless liquid, b.p. 136-138' (20 sium bromide with ethyl n-butyl ketone; b.p., 101-103° (20 mm.), n19D 1.4385; lit.6 b.p., 88.8-89.6' (15 mm.), mm.), #D 1.4420, d*oh 0.788; M R calcd. 76.1, found 76.0. Anal. Calcd. for CIBHII: C, 84.86; H , 15.14. Found: %*OD 1.4378. Methylethyl-n-amylcarbinol was prepared C, 85.08; H, 15.27. (1) This work was supported in part b y a grant from the Lubrizol In an analogous fashion, 18 g. (10%) of 6-methyl-6-ethylCorporation. tridecane was obtained from the reaction of 3-methy1-3(2) From the Ph.D. thesis of M. J. Latina, 1953. bromoactane with n-heptylmagnesium bromide. The color(3) C. R. Rinney and W. L. Spliethoff. J . Orp. Chem., 14, 71 (1949). less liquid boiled a t 139-142" (15 mm.), f f Z o ~ 1.4418, d*00( (4) K . C . Campbell and L. T.Eby, THISJOURNAL, 82, 1798 (1940). 0.780; M R calcd. 76.1, found 76.8.
TABLE I11 SUMMARY OF PROPERTIES LV.r).,
( 5 ) The semimicro analyses were performed b y Mr. P. D. Strickler and Rlr Y.N. Lee. (6) F . C Whitmore and H. M. Woodburn, THISJOURNAL, 66, 361 (1933).
( 7 ) F . C. Whitmore and P.E. Williams, ibid., 66, 406 (1933). ( 8 ) 0. R. Quayle and K . 0. Smart, ibid., 66, 935 (1944). (9) 0. M. Hake, J . 9rakt. Chem., 121 89, 451 (1914).
