Vol. 42, No. 9
INDUSTRIAL AND ENGINEERING CHEMISTRY
1690
(275) Stokstsd, E. L. R., Jukes, T. H., Pieroe, J., Page, A. C., Jr., and Franklin, A. L., J. B i d . Chem., 180,647 (1949). (276)Stohtad, E. L. R., Page, A,, Jr., Pierce, J., Franklin, A. L., Jukes, T. H., Heinle, R. W., Epstein, M., and Welch, A. D., J. Lab. and Clin. Med., 33,860 (1948). (277) Stubbs, J. J., Feeney, R. E., Lewis, J. C., Feustel. I. C., Lightbody, H. D., and Garibaldi, J. A., Arch. Biochem., 14, 427 (1947). (278) Swart, E. A,, Hutchison, D., and Waksman, 8. A., Ibid., 24,92 (1949). (279) Swart, E.A,, Romano, A. H., and Waksman, S. A,, Proc. SOC. Ezptl. Biol. & Med., 73,376 (1950). (280) Szucs, J., U. 8.Patent 2,353,771(July 18,1944). (281)Tabenkin, B., U. S. Patent 2,493,274(Jan. 3, 1950). (282) Tanner, F. W., and Van Lanen, J. M., U. S. Patent 2,424,003 (Julv 16. 1947). --Tanner, F. W., Vojnovioh, C., and Van Lanen, J. M., J. Bact., 58,737 (1949). Teixeira, C., Andreaeen. A. A,, and Kolachov, P., IND.ENQ. CHEM.,42,1781 (1960). Terjeaen, S. G., and Cherry, G.B., TTUn6. I m t . Chem. Engre. (London),25,89(1947). Terui, G., Japan. Patent 167,133 (June 19,1943). Toennies. G., and Gallant, D. L., J . Bwl. C h m . , 174, 461 (1848). (288) Ibid., 177,831 (1949). (289) Tomkins, R.V., Scott, D. S., and Simpson, F. J., Can. J . Research, F26,497(1948). (290) Tomlinson, H., Campbell, J. J. R., and Trussell, P. C., J. Bad., 59,217 (1950). (291) Tsuchiya, H. M., Corman, J., and Koepsell, H. J., presented before the Meeting of the Society of American Bacteriologists, Cincinnati, Ohio (May 1949). (292) Tsuchiya, H. M., Van Lanen, J. M., and Langlykke, A. F., U. S. Patent 2,481,263(Sept. 6,1949). (293) Tucker, I. W.; and Balls, A. K., U. S. Patent 2,457,764(Deo. 28, 1948). (294) Umezawa, H., Tazaki, T., Kanari, H., Okami, Y., and Fukuyama, S., Japan. Med. J . , 1, 358 (1948). (295) Underkofler, L. A,, and N m e r , E. I., WalZw.sleinLab., Comm., 11,41 (1948). (296) Unger, E. Do,Stark, W. H., Scalf, R. E., and Kolachov, P. J., IND.ENQ.CHEM.,34, 1402 (1942). (297) Unger, E. D., Wilkie, H. F., and Blankmeyer, H. C., Tram. Am. I m t . Chem.EWTE.,40,421 (1944). (298)Vander Brook, M.J., and Savage, G. M., U. S. Patent 2,488,248 (Nov. 15,1949). (299) Van Lanen, J. M., and Tanner, F. W., Jr., “Vitamins and Hormones,” Vol. VI, New York, Academic Press, Inc., 1948. (300) Vinson, L. J., The Frontiw, 12,9,24 (1949). (301) von Laesecke, H.W., Chem. Eng. News, 23, 1952 (1946). .--I
--.
(302) Waksman, S. A., “Streptomycin-Its
Nature and Practical Applications,” Baltimore, Md., Williams and Wilkins Company, 1949. (303) Waksman, S. A., U. S. Patent 2,326,986(Aug. 17,1943). (304) Waksman, S.A.,Frankel, J., and Graessle, O., J. Bact., 58,229
(1949). SOC.Ezptl. Bid. Med., (305) Waksman, S.A,, and Harris, D. A., PTOC. 71,232(1949). (306) Waksman, 5. A., Hutchison, D., and Katz, E., Am. Rea. Tzrbero., 60, 78 (1949). (307) Waksman, S. A.,and Karow, E. O., IND. ENQ.CHEM.,39,821 (1947). (308) Waksman, S. A., and Karow, E. O., U. S. Patent 2,394,031 (Feb. 5,1946). (309) Waksman, 9. A., Ka& E., and Lechevalier, H. A., presented before the Society of American Baoteriologists, Baltimore, Md. (May 1950). (310) Waksman, S. A,, and Lechevalier, H. A., Science, 109, 305 (1949). (311) Waksman, S. A., Lechevalier, H. A., and Harris, D. A., J, Clin. Inueat., 28,934 (1949). (312) Waksman, S. A.,and Schatz, A. U., U. S. Patent 2,449,866 (Sept. 21,1948). (313) Wallerstein, L. W.,I W . , 2,476,785(July 19, 1949). (314) Walton, M.T.,Ibid., 2,368,074(Jan. 23,1946). (316) Weirich, L., U. 8. Dept. Commerce, Chemicals Division, personal communication (1950). (316) Weizmann, C., Brit. Patent 572,637 (Oct. 17, 1945). (317)Ibid., 572,641. (318)Ibid., 572,763(Oat. 23, 1945). (319) Ibid., 573,216(Nov. 12,1945). (320)I W . , 573,930(Dec. 13,1945). (321)West, R.,Science, 107,398 (1948). (322) Western Condensipg Company, Brit. Patent 602,029 (May 19, 1948). (323) Wetzel, N.,Fargo, W. C., Smith, I. H., and Helikson, J., Science, 110,661(1949). (324) White, J., Am. Brewer, 81,21 (1948). (325)Wilson, R.H., Humphreys, E. M., Reynolds, D. M., and Lewis, J. C., PTOC. SOC.Exptl. Biol. Med., 71,700 (1949). (326) Winsten, W. A., and Eigen, E., J. B i d . Chem., 177,989 (1949). (327) Winder, R. J., J . CeZlvlar Comp. Physiol., 17,263 (1941). (328)Woodruff, H.B., Nunheimer, T. D., and Lee, S. B., J. Bud., 54, 535 (1947). (329) Woodward, J. C.,Snell, R. L., and Nicholls, R. S., U.S. Patent 2,492,673(Dec. 27,1949). (330) Yarmola, Q. A.,Mikrobiologiya, 17,471 (1948). (331)Yasuda, Sa’rae, Japan. Patent 172,304(Feb. 8,1946). (332)Yin. H. C., Econ. Botany, 3,184 (1949). (333) Yots, H., et al., Japan. Patent 172,287 (Feb. 8, 1946). RECEIVBD July 1, 1950.
Friedel- Craf t s Reactions mg PHILIP H. GROGGINS and SAMUEL B. DETWILER, JR.,
BUREAU OF
AGRICULTURAL AND INDUSTRIAL CHEMISTRY, U. S. DEPARTMENT OF AGRICULTURE, WASHINGTON, D. C.
HE Friedel-Crafts reaction continues to be a fruitful field
T
for research and development. During the past year a number of new syntheses have been reported. Studies on the mechanism of reaction continue to throw new light on the fundamental concepts of reactions catalyzed by metal halides. Earlier studies by the senior reviewer (IO, 11, 88), involving the use of carboxylic acids and their anhydrides, have been ekewhere re-examined. Reports of reactions involving the preparation of halogeno derivatives have been numerous, and some show potential industrial application.
ACYLATION The Friedel-Crafts condensation of succinic anhydride and 1,2-diphenylethane was shown by Nicholas and Smith (83) to result in the formation of l,Zbis(,9-carboxypropionyIphenyI)ethane :
CoHsCHzCH2CsHs+ (cacoho AlCl: HOOCCHiCOCsHiCH~Cltr2C~H~COCH,COOH Malinovskil and Kislova (U) have extended earlier work of Newton and Groggins (81) on the condensation of carboxylic acids with aryl compounds to yield alkyl aryl ketones. It WBB found that butyric acid and toluene react in the presence of aluminum chloride to give a 35% yield of 4methylbutyrophenone. Isovaleric acid reacts similarly, giving a 39% yield of pCHaCaH&OCH&H(CH&. The authors suggest that the use of acids is more economical than that of acyl halides or anhydrides. This conclusion, however, would apply only to reactions with acids-for example, terephthalic acid-that are converted to acid chlorides or anhydrides with difficulty. By the use of melting point curves, Baddeley (1) has estimated
INDUSTRIAL AND ENGINEERING CHEMISTRY
September 1950
Table 1.
Reaction of Carbon Monoxide and Carbon Tetrrdrloride (All rum based on 1.3 moles of CC13
iiun No.
AlClr Mole'
TrmZ,,
1
0.15 0.15
200 200 200 200 100 100 200 200
2 3 4
0.16 0.15 0.15 0.60 0.15 0.60
5 6
7
Pressure, Atm. 960 960 960 950 200 200 200 200
Time Hod 2 4 6
12 8 IO 8
9 8 9 0.23 150 8 10 0.15: 200 950 50 8 11 950 13 0.15 200 Not corrected for reoovered starting material. b AlCli reoovered from another run. FeCh catalyst.
CClGOCl Obtained Mole %" 0.42
0.46 0.47 0.48 0.24 0.39 0.14 0.19 0.09 0.18
0.09
ai 35 36 35 18 30 11 15
7 7
10
the proportions of isomers formed in a series of acetylations and benzoylations of naphthalene carried out in ethylene dichloride at 35 C. and in the presence of various selected reagents. The highest yield (93%) of the mixed methyl naphthyl ketones waa obtained with 1 or 2 moles AcCl-AICIa, and the product 'contained 97.5% of the 1-isomer. The lowest over-all yield (60%) was obtained when Ac&4IC1, was used aa acylating agent, but the product again contained 97.6% of the I-isomer. The highest yields (86%) of mixed phenyl ketones were obtained with 1 or 2 moles of Bz-~Clswith the formation of 96% of the 1-isomer. The lowest over-all yield (60%) of phenyl ketones resulted from 1 mole Bz-AICls and 1mole benzoyl chloride, with the formation of 40% of the %isomer. When, in the foregoing acylations, nitrobenzene replaces ethylene dichloride aa solvent, the over-all yields and the amounts of 1-isomer decreased. The influence of the selected reagents is attributed to the formation of large complexes comprising Ac-AlCla or Ba-AICl8 and the reagent, with resulting steric hindrance in the a-position which is not manifest in the &position. The directive influence of the acetylamino group in the FriedelCrafts acylation of diacetylaminonaphthaleneshas been studied by Leonard and Hyson (19, 20). They found that of the eight isomers of Cl&I~(NH&, six (I,%, 1,4-, 1,5-, l,%,2,6, and 2,7-) do not undergo ring acetylation with acetyl chloride and aluminum chloride in carbon disulfide, N-acyl derivatives being formed. The results indicate that the acetyl group does not enter a position ortho or peri to either AoNH group.
2chloro-2-methyl-5-hexeno. Similarly 2,2,3-trimethy I-3-hydroxy-bheptene gives a 72% yield of 3-chloro-2,2,3-trimethyl-b heptene. This reaction, however, with 2,6-dimethyl-2-hydroxy&heptane forms 90% 2,bdichloro-2,6-dimethylhtrptane. Carbon monoxide has been reacted with polychlorinated methane at pressures of 860 to 950 atmospheres in the presence of aluminum chloride to give chloroacetyl chlorides. Sulfur dioxide reacts similarly with carbon tetrachloride or chloroform to produce thionyl chloride, with yields of 73% and 40%, respectively. Frank et al. have reported (7) that such reactiom afford convenient routes where high pressure facilities are available. Data pertaining to the preparation of trichloroacetyl chloride are shown in Table I. Frank proposes the following mechanism for the reaction of polychlorohydrocarbons with carbon monoxide in the presence of aluminum chloride: C1 C1:C:Cl
O
H A L O G E N DERIVATIVES Tsukervanik, who has long been identified with FriedelCrafts research, haa investigated the activity of halogen in the condensation of ethyl esters of aliphatic halogen-substituted acids with benzene (28). He found that the position of C1 determines the nature of the products in the Friedel-Crafts reaction of benzene with esters of halogeno diphatic acids. "he activity of C1 rises with increased distance from the COO-group. Ethyl ohloroacetate with benzene gave 70% mixed hydrocarbons from which ethylbenzene, isomeric diethylbenrenes, and 1,2,4triethylbenzene were isolated. Ethyl bchloropropiona~under eimilar conditions gave a 60% yield of phenyl propionate aa well aa some ethylbenzene and chloroacetophenone. Joyce, in a patent ansigned to E. I. du Pont de Nemours & Co. (Id), describes the preparation of a series of chlorofluoroalkanes by condensing a fluoro-olefin, CSFI,with polyhalogenated methanes containing at least one chlorine atom and no more than two fluorine atoms. The following are examples of compounds prepared: CCl,HCF&F&I, CFCI&F&F&l, and CFCIHCFzCFzCI. Hydroxy olefins react with hydrochloric acid in the presence of a Friedel-Crafts catalyst and are converted to halogeno compounds. Colonge and Lagier (3)found that the resultant products may be saturated or unsaturated. Thus, 2-methyl-2hydroxy-li-hexene and hydrochloric acid give an 854/6,yield of
1691
c1
+ A 1 C l 8 d CI:k!+ + AlC1;
CI
CI
c1
c1
Clk+
ci c1 C1:C:Ct:O: c1 I .
:c:: :6:
..
4c1IG:c+::o: 4.
C1
+ AICI;
4
ClCl C1:C:C::O: GI **
+ AICls
The suggested formation of an active trichloromethyl carbonium ion rather than one involving carbon monoxide ia of interest. It is generally aseumed that carbon monoxide reacta with compounds containing 5 double bond in the presence of an acid catalyst via a formyl (HCO) radical (10):
-
CO CO
+ HCl AlCh H e 0 ...A1C1;
CO(c0)b
+ H2
CbHs --f
CBHsCHO
RCH:CHr
HCO , . . HCo(C0); -+ RCHpCH2CH0
In the synthesis of benzaldehyde (formylation), stoichiometric quantities of aluminum chloride are required. In the oxo reaction (hydroformylation) only minor proportions of cobalt carbonyl are necessary. The following mechanism accordingly appears plausible to the reviewers:
6c1, + ClCO -3 c c l s c o c l Conditions that would increase the concentration of C l e o might promote the formation of acyl chlorides.
MISCELLANEOUS CONDENSATIONS The following factors were found by Johnson and Glenn (13) to be critical in the cyclization of aryl aliphatic ketones to cyclic ketones: (1) use of acids of high purity; (2) use of phosphorus pentachloride for preparation of acid chlorides; and (3) carrying out the Friedel-Crafts reaction by adding the acid chloride to aluminum chloride in benzene. When the cyclization is carried out below 25" C., pMeOCsH&H&COCI gives a quantitative yield of 6-methoxy-1-hydrindone; a leas pure acid gives only 43% ketone. Phenylpropionyl chloride gives a 94% yield of 1hydrindone, C&CH&HeCO. I .
Lambert and co-workers (17) have made an extensive study of the reactions of a- and &nitro-olefins with benzene and toluene in the presence of aluminum chloride. In a typical preparation, l-nitro-2-methyl-2-propene was converted to l-nitro-2-phenyl-2methylpropane. Compounds having the general formula Ar-RCN, in which Ar is an aromatic hydrocarbon and R is a saturated alkylene group of 10 to 21 carbon atoms, are made by a Friedel-Crafta
VoI. 42, No. 9
I N D U S T R I A L A N D ENGINEERING CHEMISTRY
1692
reaction between an aromatic hydrocarbon and an aliphatic acid nitrile containing one double bond (24). A typical compound, tolylstearonitrile, can be prepared by condensing toluene with oleonitrile a t temperatures up to 70" C. in the presence of aluminum chloride. Weinmayr (31) has reported a process for the preparation of 2-thiophenecarboxylic acid which involves the condensation of thiophene with acetic anhydride or acetyl chloride in the presence of aluminum chloride in an inert organic solvent. The condensation product, acetothienone, is separated and made slightly alkaline with sodium hydroxide and dissolved in nitrobenzene, then oxidized with sodium hypochlorite to give a 75% yield of 2-thiophenecarboxylic acid. Ungnade and Crandall (29) have reported on the condensation of aromatic aldehydes with benzene in the presence of aluminum chloride. Chlorobenzaldehyde gives the highest yields of chlorobenzene and triphenyl carbinol with 2 to 3 moles of aluminum chloride. The nitrobenzaldehydes give good yields of OzNCbHdCPhzOH. Bevington and Norrish (2) have discussed the cross linking of various polymers prepared by the Friedel-Crafts reaction from the electronic mechanism viewpoint. It is shown that the crosslinking reaction probably involves unsaturated groupings in the polymer molecule, these groupings either being present normally in the polymer or being introduced into it by the elimination of a simple mole (HX). The relevant equations for polyvinyl chloride are :
+ Ac13
.CHs .CHCl.
-
.CH2 . b H .
+ (AlC1,)-
The loss of a proton from the carbonium ion would lead to unsaturation :
.CH~.&H.+ .CH:CH. Cross linking may occur as follows: .CHs .CHCl *CHz.CH.
+ - +
*CHCl.CHg
6 ~ . + .CH:CH
.cH~.
*
+ H+ +
.CHClbH.
HCl or
*CHr*CH* .CH:h.
+ H + + AlCla
(AlCls)
MECHANISM OF REACTION Alkylation. From an extended series of investigations, Lebedev (18) has developed some interesting physical-chemical data pertaining to the Freidel-Crafts reaction. The heats of reactions of aluminum bromide with ethylene dichloride and with chloroform at 25' C. are 11.85 and 10.5 kg.-cal., respectively. Extrapolated heats, &, of solution of aluminum bromide in an infinite volume of certain alkyl halides were found to be as follows:
&, Kg.-Cal./Mole CHBra BrCH&HpBr CHaI CpHsBr CzHd
-2.7
-2.15
4-0.3 $0.95
+1.85
The positive values of Q indicate complex formation, which is confirmed by the electrical conductivity of the solutions. Furthermore, the dipole moments for the complex-forming compounds are greater than for other compounds. Lebedev ascribes the following structure, involving dimeric aluminum chloride, to the alkyl halide complex: (AIClz.nRX)+. . . (AIClS-. This is to be compared with the following widely accepted American version (10), which is consistent with the carbonium ion mechanism and the faot that a radioactive equilibrium exists between radioactive aluminum chloride and hydrogen chloride evolved :
RCHaCl f AlCls +-+ RCH:
. . , AlCl;.
Korshak, in conjunction with Lebedev (8, f6),has continued his studies on reactions of different aluminum halides, AIXa, with various hydrogen halides, HY. Evidence for the formation of a complex, (AIXJ-, that can react with equal facility through any of the halogen atoms, was again obtained. The authors suggest a resonant dimeric structure for AlXa:
X8Al-A1X3++
x
x x
A'1
s 'k
x'
'd
x +d
x
'd
x"x
x
k
Such a structure would account for a series of properties of aluminum halides, among others the high stability of (AIX& due to the resonance energy and the eiectrophylic character of , these compounds. Complexes with alkyl halides, RX, are given the structure (AlClZ.nRX)+. . .(AlClJ-, consistent with the observed facts; varies with the concentration of the solution. These investigators believe that the structure R+. . . (AIClr)- is a t variance with many observations; thus it fails to explain the cathodic deposition of aluminum in the electrolysis of solutions of aluminum bromide in ethyl bromide and the differences of heats of solution. Korshak and Samplavskaya (16)found that the condensation of vinylidene chloride with benzene in the presence of aluminum chloride gave diphenylethylene and its dimer, 1,1,3-tripheny1-3methylhydrindene. An increase in the quantity of catalyst served to reduce the yield of monomer and to increase the amount of dimer and tam. The authors suggested that all three known dimers of PhzC:CHz can be related to each other by assuming the primary formation of a polymer, -CPh2CH&Ph2CHr, which can either cyclize or suffer proton transfer. The bulky phenyl groups, by preventing normal zigzag structure in the carbon chain, emphasize formation of the dimer. Acylation. Illari (12) has reviewed the work of Groggins and co-workers relating to the synthesis of ketones (acetophenone) from carboxylic acid anhydrides (11) and from carboxylic acids (82) and has endeavored to explain the function of acetic acid in the transformation of AcOAlCla into acetyl chloride (IO) as shown below, as well as other aspects of the mechanism of reaction :
+ CH3COOA1C12
+ 2A1C13+CH&O
(CHsC0)20
(1)
AlCh Active comples CHaCOOAlClz
+ + AlCla + CHaC=O
+ AlOCl
(2)
AICI, Active complex
To determine whether acetyl chloride is formed by the simple removal of AlOCl from 1 mole of CHsCOOAlClZ (Equation 2), the action of acetic acid on aluminum chloride in ethyl ether wm studied. The reaction mass, after removal of hydrogen chloride and ether, corresponded to (CH&O)zAICl, which on heating a t 300" C. gives neither acetyl chloride nor acetic anhydride. The diacetyl aluminum chloride is evidently stable and the evolution of hydrogen chloride around 200' C. indicates that acetic acid tautomerizes (9) to make possible the reaction: HzC:C(OH)OAl(OAc)Cl+
H&:C.O.AI(OAC)O
+ HCl
A study of poasible reactions suggests that the formation of ketones involves the following steps:
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
September 1950 CECOOH
+ AlCla
-
+ HCl
CHICOOAICIZ
2CIbCOOAIC12 +(CBC0)rO O(AIC12)z +AlOCl (CHaC0)20
+ AiC1a
2CHsCOOA1C12 CHsCOCl
+ O(A1Cb)n
+ AlC4
(1) (2)
(a)
c ~ c o c l c ~ c o o A 1 c(*) l~
( C H ~ C O ) ~+ O~
0 + A]C& ~ 1
+ AlCli +C&COCl. ..AIC&
(6) (6)
T h e summation of reactions 4,5, and 6is: (CHsC0)zO
+ 3AICIa +AlOCl + 2C&COCl ...AlClr
1693
Pepper ($6,$6) has shown that the rate and degree of polymerization of styrene and a-methylstyrene by tin tetrachloride are increaaed by increase in dielectric constant of the solvent. Traces of moisture reduce the rate in solvents of high dielectric constant but appear to increase it in hydrocarbons. Solution of SnC14 in solvents of high dielectric constant show appreciable conductivity in presence of traces of water. The polymerization has an ionic mechanism, but in solvents of high dielectric constant-for example, nitroparaffins-it does not involve hydrate
ions. LITERATURE CITED
Baddeley, G., J . Chem. SOC.,1949, Suppl. issue 1, 899-103. Bevington, J. C., and Norrish, R. G. W., I W . , 1949,482-5. Colonge, J., and Lagier, Bull. 8 0 ~ c. h k . France, 1949, 27-9. Hence the (CHsCO)eO:AlC18ratio of 1:3 found by Groggins is Corneil, H.G. (to Standard O d Development Co.), Can. Patsubstantiated. ent 461,394 (Sept. 21, 1948). (SI Eitel, A., and Fialla, R., Monatsh., 79, 112-18 (1948). CATALYSTS (6) Florin, R.E.,J . Am. Chem. Soc., 71,1867-8 (1949). (7) Frank, c. E.,Hallowell, A. T., Theobald, C. W., and Vaala, G. Relatively few patents or teohnical articles concerning the T., Im. EMU. CEE&f., 41,2061-2 (1949). production, modifioation, use, and recovery of Friedel-Crafta (8) Groggins, P. H., Ibid., 40,1608-10 (1948). catalysts have appeared during the past year. E'riedel-Crrrfte (9) IW,, 41, 1880-2 (1949). catalysts containing bromine have been found useful h the (10)Groggins, P. H., "Unit Proceslresin Organic Synthesis," 3rd ed., Chap. XII,New York, McGraw-Hill Book Co., 1947. preparation of conjugated diolehs from glycols (89). T h e c a b Nagel, R*H., and Stirton, A. J., IND. ENQ. ]ystsshould be soluble in the glycol the extent of 1 10% (11) GrodMt Cmnm., 26, 1313 (1934). by weight at room temperature. Suitable cahIYste for s ~ h (12) IUwi, ai-ppe, ~ a ad.i m , h t . , 78,887-96 (1948). dehydrations are aluminum bromide and aluminum bromide (13) Johnmn, Wm. S.,and Glenn, H. J., J . Am. Chem. SOC., 71,10926 (1949). complexes with isoprene, isobutylene, propylene, boron tri(14) Joyce, R. M., Jr. (to E. I. du Pont de Nemoura & Co.), U. 8.Patbromide, and titanium tetrabromide. ent 2,462,402 (Feb. 22, 1949). Corneil (4) found it advantageous to hest porous C-em (16) Korehak, V. V., and Lebedev, N. N., J . Urn. C h . (U.S.S.R.), of Friedel-Crafta catalysts in the presence of an oxidiziig agent18, 1766-74 (1948). (16) Korhak, v. and Samplavakwa, fc., m., 18, 1 4 7 M for example, chlorine or hydrogen peroxideta oxidize any (1948). lower compounds of multivalent metals that may be present. (17) Lambert, A., Rose, J. D., and Weedon, B. C. L., J . Chem.igoc., Tin tetrachloride in carbon tetrachloride was used 88 a catalyst 1949,424. in studying copolymerization rates of styrene derivatives (80). (18) Lebedev, N. N., J . Phys. Chem. (U.S.B.R.),22, 1605-10 (1948). (19) Leonard, N.J., and Hymn, A. M., J . Am.C h m . Soc., 71,1392-4 The amount of styrene derivative in the copolymer ww cornpared with the quantity in the initial monomer mixture from (20) zbid., (1949). pp. 1961-4. which it W a s derived. The results indicate that the order of (21) Malinomkir, M. S.,and Kislova, F. F., J . Oen. Ohm. (U.S.S.R.), reactivity with carbonium ions is: 18, 1643-4 (1948). (22) Newton, N. P., and Groggina, P. H., IND.ENGI.Cmarm., 27, 1397 (1935). PhCMe:CHz > PhCH:CH, > pCICsH4CH:CH, > (23) Nicholas, 8.D., and Smith, F., J. Chem. SOC.,1949,267. 2,6-C1rCaHaCH:CH* (24) Niederhawr, W. D. (to Rohm & Haaa Co.), U. 9. Patent 2,476,264 (July 12, 1949). Similar studies were made by Florin (6) with aluminum chloride (2s) Pepper, D.C., Tfam. Faraday Soo., 45,397-404 (1949). (26) IW., pp. 404-11. in ethyl chloride, with results of the same nature. (27) Stone, H. G. (to Eastman Kodak c0.1, U. 8. Patent 2,469,704 &Lactones am prepared by pming g-us ketene mate&b (May 10, 1949). and cmhnyl OornPOunds cOuntercufiently into a (28) Tsukervanik, I. P., and Terent'eva, I. V., Doklady Akad. Nauk liquid stream of the lactone being produced, which contains a S.S.S.R., 60,267-60 (1946). (29) Unmade, H. E., and Crandall, E. W.,J . Am. C h . Soc., 71, Friedel-Crafts catalyst ($7). This catalyst must finally be 2209-10 (1949). neutralized by the addition of an alkali, whereas catalysts such (30) Wechnler, Harry,Zbid.,70,4266-7 (1948). as HsBOs generally do not require neutralization. (31) Weinmayr, Viktor (to E. I. du Pont de Nemoure & Co.), U. 8. Patent 2,462,697 (Feb. 22, 1949). EFFECT OF SOLVENT (32) Young, D. W.,and Britton, C. E. (to Standard Oil Development Co.),U. 8. Patent 2,461,362 (Feb. 8,1949). Earlier work on the use pf solvente has indicated that efficient Roomv= 17, XWO. solvents make possible a smaller solvent ratio, increased yields, higher purity of product, and higher yields (IO). Eitel and Fialla (6) have investigated the influence of solvent on the relative proportions of o-1-naphthoyl- and 0-2naphthoylbenzoic acids formed by the Friedel-Crafts reaction of phthalic anhydride and naphthalene. It was found that the solvent used haa little effect on the proportions of the isomers, but it does influence Fluorinated Autothe over-all yield. The mixed naphthoylbenzoic acids obtained clave at Hooker from the synthesis contain 80 to 70% of the ortho-1 isomer. Electrochemical Reaction temperatures above 20" C . generally decreese this &Is, ny Y. percentage and lower the over-all yield. The yields a t 0" to 20' C. with various solvents were: (1) (2) (8) (4)
k.
Benzene Tetrachloroethane Nitrobenzene +Dichlorobenzene Carbon disulfide
