an
II/ E C
/Unit Processes Review
HaIogenation by Leo R. Belohlav and Earl T. McBee, Department of Chemistry, Purdue University, Lafayette, Ind.
b
Fluorination with sodium fluosilicates could reduce costs in the commercial production of fluorinated hydrocarbons
b
Activity in the development and use of bromine compounds is overshadowed by declining use of ethylene dibromide for antiknock mixtures
COMPARING
the production figures for halogens and some representative halogen compounds indicates a rather impressive growth rate during the past year. For fluorine this trend is undoubtedly significant. Continued interest in fluorine as a rocket propellant and the fast extending field of aerosols, together with important breakthroughs in the art of fluorination, account for the increased production. As far as chlorine is concerned, the 17y0 increase of production over 1958 is somewhat deceptive. The figure is actually only 7% better than the previous high in 1937. In contrast, the average annual growth rate between 1925 and 1950 was 12%. It appears that the demand for chlorine is tapering off, and chlorine can no longer be classified as a growth chemical. Pending major breakthroughs in chlorine chemistry, the future growth of chlorine chemicals can be expected to reflect merely the average growth of the chemical industry. Of interest is a recent breakdown for major areas of use. Chemical manufacturing absorbed 8 3 7 ~of the total chlorine production (80% of it for organic chemicals), 13% went into the pulp and paper industry, and 370 into sanitation. Bromine production suffered a setback in 1959. As approximately 90% of all bromine produced goes into ethylene dibromide for tetraethyllead (TEL), this rcflects the general trend in the TEL business. Reversion to less powerful engines for automobiles, increasing use of jets for air travel, as well as new gasoline reforming processes account for the slipping ethylene dibromide demands. Apart from this trend, bromine producers are as active as any to open new markets. Most promising presently is the field of flame retardants where bromine offers definite advantages. 4 t the same time, bromine-containing fumigants and insecticides are growing fast .
1 022
Fluorine
tures which might render them useful as lubricants at temperatures up to 1000° F.
The almost exclusive raw material source for all the fluorine that goes into organic fluorine chemicals is fluorspar. Treatment with H2SO4 gives HF which is further converted into inorganic fluoride and from there into elemental fluorine and other fluorine derivatives. For this purpose fluorspar of at least 96y0 CaFz and less than 2% Si02 is required. With poorer grades of fluorspar H2S04 gives SiFI, the conversion of which into other fluorides requires expensive additional operations. The United States lacks adequate sources for goad grade fluorspar, and most of this raw material has to be imported. -4nother source of fluorine is crude phosphate (containing approximately 3y0 fluorine). .4ttempts to use this source are on the way. However, the same difficulties are encountered as in the processing of fluorspar rich in SiOz. The exit gas in superphosphate plants contains about one third of the fluorine in the form of SiFd. i\bsorption in water gives HnSiFs. For the reasons indicated, a recent investigation into the possibility of using fluosilicates directly as fluorinating agents is of particular interest. Sodium fluosilicate was used as a fluorinating agent for CCII. Treatment at 200' to 300' C. for 2 to 3 hours yielded satisfactory amounts of chlorofluoromethane, the fluorine content of the methanes ranging from one to three fluorine atoms. The SiF4 obtained in this process can be absorbed in water and reconverted to HzSiFe. In the over-all process all the fluorine contained in the fluosilicate can thus be utilized. The method worked equally well in the fluorination of hexachloroethane; CCIpCFC12 and CFC12CFC12 together with small amounts of CFC12CF2Cl were obtained ( 7 7 ) . Halogen-substituted methanes are presently of interest because of their thermal stability at high tempera-
(8).
INDUSTRIAL AND ENGINEERING CHEMISTRY
Fluoroalcohols, which are now available on a commercial scale, have been recommended as building blocks for chemically stable surface active agents, high temperature lubricants, dielectric fluids, chemically inert finishes, and elastomeric coatings ( 3 ) . The usefulness of SFd as a fluorinating agent for carbonyl compounds was mentioned in the last review. In the past year, several publications covering the details of this reaction have been published. Cyanates react with SF? to give compounds of the general formula RN=SF?. Cyanides yield compounds of the general structure RCFAT= SF2. The fluorine atoms on thr sulfur can be easily replaced by methoxyl groups (with sodium methoxide) or by phenyl groups (with phenyllithium) (22, 52,54). Of particular importance is the ready conversion of carboxyl groups to CFzgroups by- SF4: P-benzoquinone yields 1,2,4 trifluorobenzene, whereas chlorani1 gives 1,2,4,5-tetrachloro-3,3,6,6-tetrafluoro- 1,4-cyclohexadiene. Benzenearsonic acid affords CeHdsF, (533). A simple preparation for SF4 has been described which should make this useful chemical generally available for research (60). Considerable research on perchloryl fluoride (FCIOJ)was done during the past year. The lackof adipole moment in perchloryl fluoride indicates that the cumulative electronegativity of the chlorine and the three oxygen atoms just about balances out the high electronegativity of fluorine. Thus. the course of reaction with perchloryl fluoride is strongly influenced by the reaction environment. In the presence of acids (proton or Lewis acids), the chlorine is the electrophilic center. In conu-ast, in basic solution, perchloryl fluoride reacts as a
-
a n v d Unit Processes Review positive fluorine compound, the first one ever reported. Perchloryl fluoride was used to convert I-ethoxycyclohexene in pyridine a t 0' C. to 2-fluorocyclohexanol. Similarly, 2-chlorocyclopentanone was prepared. Generally difluorination of carbanions of the general type C H ( c = X ) z is easily effected by perchloryl fluoride in the presence of sufficient base (26). T h e sodium salts of sec-nitroalkanes and cycloalkanes were reacted with perchloryl fluoride to give fluoronitro compounds in 36 to 4270 conversion. Although this reaction affords scientific interest, it does not appear to be very efficient for preparative purposes (50). In the past year, considerable information about the relative safety of perchloryl fluoride has been accumulated. I t can be stated generally that all oxidizable materials in contact with perchloryl fluoride represent a potential hazard. The pure compound is relatively stable and only moderately toxic. Fluorinated nitrogen compounds with direct N-F linkages are of substantial theoretical and practical interest. There are about 12 compounds of this type presently generally known, but at least 20 are under study. Most of this work is done under military contracts for undisclosed purposes. Besides military applications, nitrogen - fluorine compounds may find use as synthetic intermediates and chemotherapeutic agents in cancer research, according to the Office of Naval Research. Perfluoro-2-azapropene was treated with several metal fluorides. Usually, simple fluorine addition to the N=C double bond did not occur. Reaction with AgF2 gave a dimer, (CF8)2NCF= NCF3, together with perfluorotetramethylhydrazine. At higher temperatures perfluorodimethylamine was also formed; PbF4 formed the dimer also, together with the hydrazine, and COF3 gave the hydrazine and perfluorodimethylamine but no dimer. Only the dimer resulted from reaction with AgF; HgF2 afforded a mercury compound, (CF3)2N-Hg-N(CFa)z (63). "Tearly quantitative yields in the ntxaaration of hexafluoroazomethane, by treating cyanogen halide with metal fluorides, are claimed by a German patent (79). In another method cyanogen chloride is treated with NaF and chlorine. In this case, a 22% yield of hexafluoroazomethane, 5% CClF3, and smaller amounts of (CF:,)2NH, CC13F, and cyanuric fluoride are obtained. Thecyanogen chloride could be formed in C O P from NaCN or KSFe(CN)G and chlorine (59). Tribromofluoromethane was prepared in 90 to 92Yc yields by heating tetrabromomethane and SbF3 in the presence of
Flexible printed circuits made of halofluorocarbon plastic effect substantial weight reductions yet protect all conductors against moisture or gases bromine in a platinum flask for 2 hours at 125' C. and subsequently for 6 to 7 hours a t 135' to 140' C. Approximately 5% CF2Br2 was obtained as by-product. Heating the tribromofluoromethane to 640' C. in a platinum tube gave 45% hexafluorobenzene, 6% CeBrFS, and 2% CBrzFz together with other unidentified products (74).Fluorination of hexachlorobenzene with SbF5 resulted in a mixture of fluorinated hydrocarbons consisting of 20 to 30ojO 1,2-dichlorooctafluorocyclohexene, 20% 1,2,4-tri-
chloroheptafluorocyclohexene, and less than 1yo 1,2-dichiorohexafluorocyclopentene (33). A direct fluorination of benzene with retention of the aromatic character was achieved by fluorination with tetrafluoromethane or BF3 under simultaneous high energy irradiation. Several fluorobenzenes were obtained. Nitrobenzene gave m-nitrofluorobenzene. An improved fluorination method for aromatic compounds was demonstrated in the preparation of 1-bromo-3-fluoro-
Production of Halogens and Halogenated Compounds 1958
1959
Short Tons
Chlorine Bromne HCI HF
3,599,214 88,200 828,157 83,991
4,284,600 85,500 1,036,000 102,850 Pounds
a
CCla CsHC13 C2Cla Estimated.
309,818,922 294,627,670 188,276,844
368,500,000" 362,000,OOOa 200,000,000"
AVAILABLE FOR ONE DOLLAR
The complete bibliography for the 1959-60 Halogenation b y Belohlov and McBee.
Unit Processes Review of
Clip and mail order coupon on reverse side. VOL. 52, NO. 12
DECEMBER 1960
1 023
an 4-
Unit Processes Review
naphthalene and 6-bromo-2-fluoronaphthalene. Decomposition of the diazonium hexachlorophosphate afforded a yield of 60 to 6570, whereas the standard Schiemann procedure gives only 50 to 5570 (37). The preparation of p-fluoroaniline was accomplished by the catalytic hydrogenation of nitrobenzene in the presence of anhydrous H F ranging from 10 to 1 to 50 to 1. Yields of 6170 could be realized under a pressure of 55 p.s.i. and a temperature of 50" C. (75). Fluorination of several nitrogen compounds with elemental fluorine diluted with helium was reported. T h e following reactions could be realized :
highly exothermic reactions. If the temperature is not adequately controlled, carbon and undesired high boiling by-products are formed, and actual ignition and explosion may occur. T h e process control is particularly difficult when exhaustive chlorination is desired or when hydrogen is present in the methane feed stream. The isothermal character and high heat capacity of fluidized beds of inert solids appears to offer the best means for control. For this process reaction data were obtained, practical reactors were designed, and the quality of products in dependence of the feed stream composition was examined (27).
+ (CF3)3N + (CF8)pN--N + (CF3)eNF +
HCON(CH3)2 + (CFB)*NF
(CFB)~
HCONHCH3 + CF,=NF, CFBNFp C H B C O N H ~ CHaCOF N, +
mild conditions
CFSCN
>
CFBCF2N=SCFyCF,:
mild conditionr
CF sCF2CN
+
CF3CF2CF2N=hTCF2CF2CF3
vigorous conditions
CFaCF2CF2NFe
CLiaCF2CN mild conditions
CHaSCh' CHsSCN
+ +
SFjCN
SFjCF2NF2 f SFe
+ by-products
A possible mechanism for these reactions was presented (2). Direct fluorination of urea with elemental fluorine at 0 ' C. gave a complex yellow corrosive liquid with u p to 107, active fluorine and a total amount of 45 to 5570 fluorine. From the volatile fraction, SHF2 could be isolated and physically characterized ( 3 7 ) .
Chlorination
A thorough investigation of the relative importance of polar and resonance effects in the reactions of chlorine atoms was published (48). The vapor phase chlorination of methane at 300'
A wide variety of hydrocarbons are known to be chlorinated by tert-butyl hypochlorite. I t was reported that allylic radicals keep their stereochemical properties when reacted with hypochlorite, This radical chain reaction can be started lvith radical sources or light at 0 ' to 60' C. without solvent or in nonpolar solvents (carbon tetrachloride, benzene). Allylic chlorinations analogous to brominations with - bromosuccinimide were obtained : trans-2-butene gave stereospecifically CHClz-CH=CH?
CHC12-CHCl-CHzOH
CH,Cl-CH=CHCl
+
CH2CI--CHOH-CHC12
CH2Cl-CH=CCl:!
+
0 cash 0 check
TO: EDITOR I/EC
money order
Make payable to American Chemical Society
........................................ ......................................................
Name and title........ Address
1 024
INDUSTRIAL AND ENGINEERING CHEMISTRY
+
+
I I
(2%)
CC11-CHCl-CH20H
trace CHClr-CHCl-CH2C
CC13-CHOH-CH2Cl
1 155 Sixteenth St., N.W. Washington 6, D. C. Enclosed:
(98%) $. CHC12-CHOH-CH2CI
CCl,-CH=CH,
to 450' C. involves
SEND ORDER COUPON
-+
trans- 1-chloro-2-butene and cis-2-butene gave czs-1-chloro-2-butene. I n both cases, 3-chloro-1-butene was obtained as a by-product. I n the presence of bulkier groups, the intermediate cis-radical is unstable and partially isomerizes to the tfans-isomer (67). Chlorination of aromatic nitroamines with tert-butyl hypochlorite was also reported (47). A variety of unsaturated compounds were treated with mixtures of bromine and chlorine. The bromochlorides of cyclohexene, styrene, ethylene, transcinnamic acid. cis- and ti am-stilbene, and diphenylacetylene were obtained. With styrene and cinnamic acid the products isolated were those expected from the addition of an electrophilic bromine and a nucleophilic chlorine atom. IYith cis- and trans-stilbene stereospecific trans-addition was observed (6). The chlorination of 2-chlorobutane was studied. Gas phase chlorination of this compound in a flow reactor gave a ratio of meso- to dl-2,3-dichlorobutane of 2.4 to 1 at 78" C. and 2.5 to 1 at 35" C., as identified by gas chromatography. This suggested a stereospecific 2-chlorobutyl radical during the reaction. Possible structures for this were suggested ( 7 8 ) . Tetrabutylammonium iodotetrachloride was reported as a chlorinating agent. TVith czs- and trans-stilbene stereospecific trans-addition was observed. Acetophenone could be substituted readily on the a-C atom (7). The addition of HOCl to allylic chloride yielded products which were not always consistent with the expected results based on a comparison with the addition of HC1 to the same compounds. The folloiving reactions were observed:
+ CC13-CHCl-CH~C1
No detectable allylic isomerization was found to accompany the addition of HOCl to 3,3-dichloropropene and 3,3,3trichloropropene ( 5 7 ) . Kitryl chloride was reacted with several acetylenes : 3-hexyne reacted with nitryl chloride in methylene chloride to give trans-3-nitro-4-chloro-3-hexene, and 5-decyne reacted with nitryl chloride to give trans-5-chloro-G-nitro-5decene and 5-chloro-6-nitro-4-decene (49). Oxidative chlorophosphonation of alkenes and haloalkenes was investigated. Oxygen and alkenes were passed into PC13, or oxygen alone was passed into a mixture of haloalkene and PC13 (55, 65). Isoprene reacted with dichloro-
a n m d Unit Processes Review or dibromocarbene to give 1,l-dichloro - 2 - methyl - 2 - vinylcyclopropane exclusively. This demonstrated again the electrophilic nature of dihalocarbenes (32). Dichlorocarbene was reacted with AT-benzylideneaniline to give 1,3- diphenyl -2,2 -dichloroethyleneimine in 5570 yield. Hydrolysis yielded achloro-a-phenylacetanilide (77). High temperature chlorinolysis and cracking of chlorinated diethyl ethers afford a new route to chlorinated vinyl ethers: recovery weights up to 21% were reported. All six chloroethylenes were obtained in this work (7). Using triphenylphosphine and triphenylarsine dihalides, the mechanism originally proposed by Huckel for the conversion of alcohols to alkyl halides with PC15 could be verified (adduct formation of alcohol and PC15 or PC14+ and subsequent S N reaction ~ with halide ion under Walden inversion). For the formation of gem-dihalides or substituted vinyl halides, respectively, from carbonyl compounds, as well as for the dehydration of acid amides and oximes to nitriles, a reaction sequence starting with coordinative adduct formation of the carbonyl group with the phosphorus pentahalide was discussed (23). An alternate mechanism for the reaction of Pc16 with ketones centering around the formation of a chlorocarbonium ion was also proposed. Several known reactions were discussed by the suggested mechanism (38). New equipment for the chlorination of monochlorodimethyl ether was described which affords 26,3Y0 yield of 1,l-dichlorodimethyl ether (20). Peracetylated mono- and disaccharides of the @-series reacted with dichlorodimethyl ether in the presence of catalytic amounts of ZnCl2 to give the corresponding acetochloro derivative. The advantages of this new preparation are fast reactions, simple isolation, good yields, and no side reactions (27). Some a-haloamines of the general type R-CHC1-NR2 resulted from the cleavage of aminals (substituted diaminomethane derivatives of aliphatic or aromatic aldehydes) with hydrogen halide or by the reaction of enamines, > N-CH=CHR, with hydrogen halide (5). The a-nitro acid chlorides cannot be made from the corresponding acid with SOClz or PC15. They were obtained, however, in good yield by chlorination of the hydrazides or their salts in inert solvents (29). In most current processes only 14 to 16% of the hexachlorobenzene obtained from the chlorination of benzene are composed of the y-isomer. A thorough investigation for the determination of the optimum conditions for maximum y- content was undertaken As the reaction temperature was lowered
from 40' to 10' C., the optimum chlorine concentration for the maximum percentage of y-isomer gradually decreased from approximately 2.5 to 0.7%. The highest y-content obtainable by chlorinating pure benzene was 1i'.5yO realized a t chlorination just above its freezing point. Methyl chloride, methylene chloride, dichloroethylene, and acetic anhydride were especially effective as solvents, having dielectric constants above 4. A y-isomer content of 25 to 30% could be realized with these solvents under optimum chlorine concentrations. Formation of the yisomer is generally favored by more dilute solutions ( 4 ) . A process for making benzene hexachloride containing u p to 28y0 of the y-isomer is claimed by a recent patent. Reaction with chlorine is performed in a liquid reaction mixture containing a compound such as methyl or ethyl sulfate. The reaction is conducted at -60" to f70' C. with a slight excess of chlorine under radiation with actinic light (36). I t was found that the reaction of chlorine and benzene to give benzene hexachloride is promoted or catalyzed by exposing the reaction medium to gamma radiation. The isomer distribution was 53.770 m-, 19.670 y-, 12.1y0 6-, and 9.oY0 €-isomer (30). The modification of the electron-releasing properties of the OH-group in phenol by the use of electron-withdrawing groups attached to the oxygen atom permits addition chlorination to take place readily. Phenyl trichloroacetate yielded hexachlorocyclohexyl trichloroacetate (45). A new method of obtaining picryl chloride or bromide in 95 to 99% yield was developed. Pyridine picrate is heated 1 to 2 hours a t 100' to 130' C. with POCIS to give the chloride or with PBr3 to give the bromide. Similar results were obtained by action of picric acid on a combination of pyridine with POC13 or PBr3 at 100' C. (40). Mesitaldehyde could be chloromethylated to yield 2,4,6-trimethyl-3 (chloromethyl) benzaldehyde (43). A new chloroformylation reaction of phenylacetylenes to p-chlorocinnamic aldehydes was reported. The over-all reaction is supposed to pass through the foollwing sequence :
-
K-/)-c-cH
Both N-methylformanilide and iV-formylmorpholine can be used, as well, in this reaction. As a solvent, trichloroor dichloroethylene, as well as dimethylformamide, are suggested (64). The opening of epoxide rings by phosphorus oxyhalides or phosphorus thiohalides is well known. Recently, the reaction found increased interest, as the resulting haloalkyl thionophosphates or phosphates are of intrinsic value as fuel additives and flame retardants. A new modification for the preparation of p-chloropropyl thionophosphate was reported. T o sulfur and PC13 at 60' to 68' 6. was added 1,2-propylene oxide a t such a rate as to maintain the temperature at about 80' C. ( 7 5 ) . Passage of dry phosgene through alkyl phosphites or addition of phosphites to liquid phosgene cooled with a freezing mixture resulted in a 60 to 7oy0yield of (RO)zPOC1. The products were identical with those formed by chlorination of ( R 0 ) z P H O (44). An analogous reaction was obtained with oxalyl chloride, apparently under simultaneous formation of CO and RC1. Compounds of the general type (RO)*P(O)(CHZ),CO~R reacted with excess PC15 to yield the corresponding $,$-dichlorides with the carbalkoxy group not being affected even with large amounts of PC16 a t 120' C. (42). Several new fluorinecontaining trichlorophosphazosulfonaryls were prepared (e.g., @-FCeHd-SO2N=PCls, m CF,CBH,--SO2N= Pc13) (62).
-
Bromination Two patents for the oxybromination of chlorodifluoromethane were issued. The over-all reaction occurs in accordance with the following equation : 4CHClF2
+ 2Brl + O2+ 4CBrC1F2
+ 2H20
Chromium oxide supported on A12(SiO2) 8 or oxides and organic salts of vanadium either per se or supported were used as catalysts (46, 47). The reaction of bromine water with olefins yields the bromohydrins. However, this reaction can be suppressed in favor of simple
+ POCL + ( c H ~ N) ~C H O - ~ @e R--C=CH+HC
OPOCl*
/ \N(
0
C H ~ CI+ \
CH3 OPOClz HzO
/ + R -C=~CCI=CH-CH
VOL. 52, NO. 12
DECEMBER 1960
1025
an -)
Unit Processes Review
bromine addition in the presence of bromide ions. T h e probable mechanism was discussed (25). A detailed investigation on the effect of oxygen, light, reactant impurities, and added substances upon the allylic bromination with 11;-bromosuccinimide was undertaken ( 7 3 ) . An excellent review article on the uses, properties, and reactions of 2V-bromosuccinimide has appeared (24). Aliphatic and alicyclic olefins and benzenoid aromatics were shown to react with oxalyl bromide to give the corresponding carboxylic bromides. Nonbenzenoid aromatics yielded glyoxylic acid bromides or carboxylic acid bromides, depending upon the reaction conditions. A reaction mechanism was discussed 157). Several bromohydrins could be prepared conveniently by reacting the corresponding olefins with acetyl hypobromite. T h e reagents formed in situ by the addition of bromine and silver acetate to a solution of the unsaturated compound in CC14. The reagent is nonacidic and particularly useful in the presence of acid-labile functional groupings (34). T h e combination of bromine with natural rubber in sufficient quantity to confer flame resistance usually adversely affects the elastic properties. When a mixture of rubber and CBr4 was exposed to high energy radiation, combination with the halogen occurred, and yet the rubber retained its high elasticity (70). Reaction of oxalyl bromide with ketones afforded the corresponding P-ketoacid bromides from which the corresponding P-ketoacid derivatives could be prepared. Oxalyl chloride generally gives only 20Y0 of the yield obtainable with oxalyl bromide (58).
I n contrast to pyridinium perbromides, the readily prepared phenyltrimethylammonium perbromide is stable, very soluble in cold tetrahydrofuran, and permits 0-monobromination of ketones or cyclic ketals containing ethylene linkages or active benzene nuclei. Bromination of 2-acetyl-6-methoxynaphthalene gave 80% yield of 2 ( ~ - b r o m o acetyl)-6-methoxynaphthalene(35). I t was shown that benzylic bromination involves a completely free a-phenethyl radical intermediate that undergoes isomerization a t least 600 times faster than it displaces on AT-bromosuccinimide (72). Tetrabromophthalic anhydride, useful for its flame retardant properties, was prepared by bromination of phthalic anhydride in chlorosulfonic acid in the presence of small amounts of sulfur a t 145O to 150” C. Yields amounted to 90 to 95% (39). Bromine was conveniently introduced into the benzene ring of indole by converting the indole into the indolene,
1026
performing the substitution and dehydrogenating again to the indole derivative (56). Iodination
I n a new iodination procedure, the useful iodinating agent O(CzH4)z X I . H I is produced in situ. T h e aromatic compound is dissolved in anhydrous methyl alcohol, ethyl alcohol, or other solvent, and 1 mole of morpholine and 3 moles of iodine are added to the solution. After being kept 48 hours in the cold, the products were separated in about 90Y0 yield. Several iodinated phenols were prepared in this way ( 9 ) . Primary alkyl iodides (methyl through amyl) were produced in excellent yields from dialkyl sulfates and a solution of iodides produced from iodine and aqueous SOz, bisulfite, or sulfite (25).
Literature Cited (I) Artle, M. J., .Arnold, A. P., IND.ENG. CHEM.51, 671 (1959). (2) Attaway, J. A , Groth, R. M., Bigelow, L. A , , J . A m . Chem. Soc. 81, 3599 (1959). (3) Baer, D. R., IND.ENG.CHEM.51, 829 (1959). (4) Bissinger, W.E., Dehn, F. C., others, Ibid., 51, 523 (1959). (5) Bohme, H., Ellenberg, H., others, Chem. Bel. 92, 1608 (1959). (6) Buckles, R. E.: Forrester, J. L., others, J. Org. Chem. 25, 24 (1960). ( 7 ) Buckles, R. E., Knaack, D. F., Ibid., 25, 20 (1959). (8) Buckley, D. H., Johnson, R. L., IND.ENG.CHEM.5 1 , 6 9 9 (1959). (9) Chabrier, P., Seyden-Penne, J., Fouace, A. M., Comfit. rend. 245, 174 (1957). (IO) Cockhain, E. G., Bendle, T. D., Turner, D. T., Chem. €8 2nd. (London) 1960, p. 318. (11) Dahmlos, J . , Angew. Chem. 71, 274 (1959). (12) Dauben, M. J., Jr., McCoy, L. L., J . A m . Chern. Soc. 81, 5404 (1959). (13) Ibid., p. 4803. (14) Desirant, Y., Bull. soc. chim. Belges 67, 646 (1958). (15) DeM‘itt, E. G. (to Ethyl Corp.), U. S. Patent 2,862,950 (Dec. 2, 1958). (16) Fidler, D. A. (to O h Mathieson Chemical Corp.), Zbid., 2,884,458 (April 28, 1959). (17) Fields, E. K., Sandri, J. M., C h m . 63 2nd. (London) 1959, p. 1216. (18) Fredericks, P. S., Tedder, J. M., Proc. Chem. Sac. 1959, p. 9. (19) Glemser, O., Schroeder, H., Haeseler,
H. (to Farbwerke Hoechst A.-G.), Ger. Patent 1,005,972 (April 11, 1957). (20) Gross, H., Chem. Tech. (Berlin) 10,
659 (1958). (21) Gioss, H . , Farkas, I., Chem. Ber. 93, 95 (1960). (22) Hasek, W.R., Smith, W.C., Engelhardt, V. A., J . A m . Chem. Sac. 82, 1543 (1960). (23) Horner, L., Oediger, H.. Hoffmann, H., Ann. 626, 26 (1959). (24) Horner, L.. Windelmann, E. H., A n p e a . Chem. 71, 349 (1959). (25) Huber, F. R., Schenck, L. M. (to General Aniline and Film Corp.), U. S. Patent 2,899,471 (Aug. 11, 1959). (26) Inman, C. E., l’yczkowski, E. A., others, Exfierzentia 14, 355 (1958). (27) Johnson, P. R., Parsons, J. L.,
INDUSTRIAL AND ENGINEERING CHEMISTRY
Roberts, J. B., IND. ENG. CHEM.51, 499 (1959). (28) Kanyaev, N. P., Zhur. Obshchci Khim. 29, 841 (1959). (29) Kissinger, L. W., U n p a d e , H. E., J . e r g . Chem. 24, 1244 (1959). (30) Kung, F. E. (to Columbia-Southern Chemical Co.): U . S. Patent 2,911,342 (Nov. 30, 1959). (31) Lawton, E. A . , Webcr, J. Q., J . rlrn. Chem. Soc. 81, 4755 (1959). (32) Ledwith, A,: Bell, R.. M.?Chew. Ind. (London) 1959, p. 959. (33) Leffler, A. J., J . Or8. Chpnz. 24, 1132 (1959). (34) Levine, S. G., Wall, IvI. E., J . Am. Chern. Sac. 81, 2826 (1959). (35) Marquet, A.; Jacques, J . , Tetrahedron Letters 1959, pp. 9-24. (36) Neuhauer, J. il., Strain, F., others, (to Columbia-Southern Chemical C o . ) , U. S. Patent 2,858,260 (Oct. 28, 1958). (37) Newman, M. S.: Galt, R. H. B., J . Org. Chern. 25, 214 (1960). (38) Newman, M. S., Wood, L. L., ,Jr., J . A m . Chem. Soc. 81, 4300 (1959). (39) Ohle, H., Ger. Patent (East) 14,750 (May 14, 1958). (40) Okon, K., Roceniki Chern. 33, 45 (1 959). (41) Pausacker, K. H., Scroggie, J. G., Australian J . Chern. 12, 430 (1959). (42) Petrov, K. A . , Maklaev, F. Id., Korshunov, ILI. A . , Zhu?. Obshchei Khirn. 29, 585 (1959). (43) Popovich, P., Lazzell, C. L., Huff, R . F., Proc. West Virginia Acad. Sci. 29, 30, 51 (1957-58). (44) Pudovik, A. AT., Platonova, R. M., Zhur. Obshchei Khzm. 29, 507 (1959). (4.5) Rosen, I., Stallings, J. P.: J . Org. Chem. 24, 1523 (1959). (46) Ruh, R. P., Davis, R. A. (to Dow Chemical Co.), U . S. Patent 2,871,274 (Jan. 27, 1959). (47) Ibid.,2,908,724 (Oct. 13, 1959). (48) Russell, G. A,; Tetrahedron 8 , 101 (1960). (49) Schluback, H. H., Braun. A , , Ann. ’ 627, 28 (1959). (50) Shechtcr, H., Roherson. E. B., J r . , J . Or,?. Chem. 25, 175 (1960). (51) Shelton, J. R., Lee. L. H., Ibid.. ’ 24, 1271 (1959). (52) Smith, W. C. (to E. I . du Pont dc ’ Nemours’~ CO.), ~ U . S.Paten t 2,859,245 (Nov. 4, 1958). f531 Smith. W. C.. Tullock, C. \V., \dthers, J , ’ A m . Chem:Soc. 81, 3165 (1959). (54) ,Smith, W. C., Tullock. C. W., others, Zbzd., 82, 551 (1960). (55) Soborovskiy, L. Z., Zinovev: Y. M., Spiridonova, T. G., Zhur. Obshchei Khim. 29, 1139 (1959). (56) Terent’ev, A. P., Preohrazhenskaya, M. N., Zbid., 29, 317 (1959). (57) Treibs, W.. Orttmann, H., Chem. Ber. ‘ 93, 545 (1960). (58) Treihs, W., Riemer, J., Orttmann, H., Ibzd.,93, 551 (1960). (59) Tullock, C. W.(to E. I. du Pont de Nemours & Co.), U. S. Patent 2,912,429 (Nov. 10, 1959). (60) Tullock, C. W.,Fawcett, F. S., others, J . A m . Chem. Sac. 82, 539 (1960). (61) Walling, C., Jacknow, B. B., Thaler, W., 136th Meetlng, ACS, Atlantic City, N. J., September 1959. (62) Yagupol’skiY, L. M., Troitskaya, V. I., Zhur. Obshchex Khim. 29, 552 (1959). (63) Young. J. A , , Durrell, W. J., Dresdner, R. D.: J . -4m. Chern. Sac. 81, 1587 (1959). (64) Ziegenbein, W., Franke, W., Angew. C m . 71.573 (1959). -h. , (65) Zinov’ev, Y. M., Soborovskif. L. Z. Zhur. Obshcher Khzm. 29, 615 (1959). ~
- 7
I
