Sept., 1945
THECHEMICAL COMPOSITION OF TECHNICAL DDT
dichloroisobutane has shown it t o contain an unsaturated impurity: the aryloxy derivatives prepared by us probably contain some ethylenic admixture, as. would be indicated by the molecular refractivities. I-Chloro-2-methyl-3-o-cresoxypropane.-The procedure described above but with 108 g. of o-cresol in place of the phenol gave 117 g. (59%) of product of b. p. 112.8-114.5' at 6 mm.; dsO, 1.0898; n a o 1.53377. ~ Anal. Calcd. for CllHlsOCl: C1, 17.83; MRD, 55.91. Found: C1, 17.91; MHD, 56.53.
l-Chloro-2-methyl-3-pt-amylphenoxgpropane.-The use of 164 g. of p-t-amylphenol gave 81 g. of product of b. p. 135-147' at 3 mm. Anal. Calcd. for C16H2aOC1: C1, 13.96. Found: C1, 14.18. Action of Cuprous Cyanide on Eastman 1,J-Dichloroisobutane.lbJ-A mixture of 90 g. (1 mole) of cuprous cyanide and 762 g. (6 moles) of Eastman practical 1,3dichloroisobutane6 was stirred and refluxed for twenty-four hours. During the course of the reaction a large lump of tarry material appeared in the flask and the liquid turned dark brown. The liquid was filtered into a distilling flask and the tar washed with a little dichloride. The mixe: liquid was distilled a t atmospheric pressure to about 140 and the residue fractionated under diminished pressure. I n one run in which 2 g. each of the bromides of cobalt, copper and nickel were added, 25.5 g. of liquid 4-chloro-3methyl-3-butenonitrile and 6.5 g. of solid nitrile (m. p. 51.5-52.5') were obtained. The liquid chloronitrile, b. p. 69-70' at 10 mm., has a somewhat ethereal odor and lachrymatory effect. I n contact with the skin it gives a stinging burning sensation. Anal. Calcd. for CJI&K!l: N, 12.12; C1, 30.68. Found: IS',11.78, 11.07; C1, 30.72, 29.79. Imido-ester.-A mixture of 9.9 g. of chloronitrile and 5 g. of absolute ethanol was treated with dry hydrogen chloride and poured into 100 cc. of absolute ether. A yield of 13 g. (86.8%) of product was obtained. This was recrystallized by dissolving in anhydrous acetic acid and reprecipitated by the addition of anhydrous ether. -4nal. Calcd. for CTHlrNOC12: N, 7.07. Found: N, 7.46, 7.28, 7.41.
1591
Hartigan by a differential thermocouple method,so found that the compound melts at 102', uncor., with decomposition t o give an amide, a white crystalline solid of m. p. 153-157', cor. Unlike (IV) the new chloronitrile gave a black resinous mass with sodium amide in liquid ammonia and similar material with phenylmagnesium br0mide.l
Summary 1. @-Methyl-y-chlorobutyronitrile and
p-
methylglutaronitrile may be prepared by the action of sodium cyanide on 1,3-dichloro-2-methylpropane. 2. 2-Methylcyclopropanecarbonitrile, whose structure has been established by its transformation into the corresponding amide, has been made in a 60% yield by the action of sodium amide on &methyl- y-chlorobutyronitrile in liquid ammonia solution. 3. @-Methyl-y-aminobutyric acid and a-substituted- y-methylpyrrolines may also be prepared from the &methyl- y-chlorobutyronitrile. 4. 2-Phenylpyrroline may be obtained in small yield by the action of phenylmagnesium bromide on y-phenoxybutyronitrile. Similarly, 2,3-diphenylpyrroline is formed by the reaction of this Grignard reagent with a-phenyl-y-ethoxybutyronitrile, which may be made from benzylcyanide, sodium amide and cellosolve bromide. 5. The 1,3-dichloro-2-methylpropanereacts with sodium aryloxides to give 1-chloro-2-methyl3-aryloxypropanes, 6. An impurity in the 1,3-dichloro-2-methy1propane will react with cuprous cyanide to give a new chloronitrile and a solid dinitrile. (30) Hartigan and Cloke, THISJOURNAL, 61, 709 (1945).
TROY, N. Y.
RECEIVED MAY31, 1945
[CONTRIBUTION FROM THE BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE, AGRICULTURAL RESEARCH ADMINISTRATION, U. s. DEPARTMENT O F AGRICULTURE, AND THE DEPARTMENTS OF CHEMISTRY OF HARVARD UNIVERSITY, THE UNIVERSITY OF MARYLAND AND THE OHIO STATE UNIVERSITY]
The Chemical Composition of Technical DDT' BY
H. L. HALLER,~ P A U L D. BARTLETT,3 NATHAN L.D R A K E , ' M E L V I N s. N E W M A N , ' STANLEY J. C R I S &I.E A K E R , 4 ROBERT A. HA YES,^ GLENw. K I L M E R , 4 BARNEYM A G E R L E I N , ' GEORGE P. hIUELLER, ABRAHAM SCHNEIDER,' AND WILLIAM W H E A T L E Y b
TOL,2 C H A R L E S
'
The recent discovery of the outstanding insecticidal properties of the product known as D D T ( I ) These researches were carried out under a transfer of funds to the Bureau of Entomology and Plant Quarantine from the Office of Scientific Research and Development, as recommended by the Committee on Medical Research, and under contracts between Harvard University, University of Maryland, and The Ohio State University, and the office of Scientific Research and Development, as recornmended by the National Defense Research Committee. (2) Bureau of Entomology and Plant Quarantine, Agricultural Kesearch Administration, U. S. Department of Agriculture. Beltsville, Md. (3) Department of Chemistry, Harvard University, Cambridge, Mass. ( 4 ) Department of Chemistry, University of Maryland, College Park..~ Md. ( 5 ) Department of Chemistry, The Ohio State University, Columbus, Ohio.
and its successful application against the body louse and other disease-carrying insects have aroused considerable interest. Numerous articles praising its merits have appeared in scientific and trade magazines, as well as in newspapers and popular magazines* These the history Of its introduction into this country and, as might be expected, the stories are not always in agreement. Probably the most accurate account is given by Froelicher.'j The studies leading to the discovery of D D T as an insecticide are presented by Lauger, Martin, and The symbol "DDT" is a contraction for di(6) Froelicher. Soap and Sanif. Chcm., 20 (7), 115 (1944). (7) LBuger, Martin and Muller, Helv. Chim. Acta, 17, 892 (1914).
1 .YE
HALLER, R.IKTLETT,DK.ZICIS, NFWILIAX, CRISTOL, E.IKRR.HAYESAND KILMER
Vol. 6’7
chloro-diphenyl-trichloroethane,the generic naine 1948, and by July :I. creditable showing was being of the active insecticidal principle. Theoretically m ; d e on :t practical scale. Until early in 1941 this there are forty-five possible dichlorotiiphenyltri- company was the sole producer of D D T in this chloroetlianes. However, the tcriii ‘’ 111 )T” is country. 13y thxt time the demand had so incotifined to the product obtained or1 ctmderisation creased tliat tliree other companies were askctl to uric1ert:tl;e its inanufacture. To this group t)i chloral (or its alcoholate or haye siiici: beeii atltled a number of other eornrobenzene in the presence of s ‘It the present time t spring 1W.j) ttircc grades p;iriies. of D D T are recogtlizctl by the \rnr Production ’lhe rapid acceptance C J ~D D T by the armed Hoard and the nrinctl icircts of this country---tech- iorws tnntle it imperntire to study the coinpwinical I)Il’l, purified or aerosol i.II-)T, and pure t.irm i ) i tlie technical product in order that the na1)L)T. A s its naine implies, teclitiical 1)DT is ;I. tlirc antl :trnount oi the by-protluct inaterials commercial grade coiiiplying with all the specifi- mixlit he tleterminetl and that these products c:ttinns outlined i n tlic Joint A\riny---X:il.-ySpecifi- iiiight ljc coiriIxtret1 in. ticidally and pharmacocations (’AN-D-3iA, JIar, lii, 10-45)..is will be 1ogic:tIly w i t h ,b,j>’- i 111 Alccortlingly,in April, sl1i)wn in this report, i s :I coinplcs iiiistiirc. co11- I the stiidies o i i I ) I I T tiiitler w,iy in the Bureau taiiiirig upwards of 10 of l - t r i c j i l ( ~ r ~ ! - ~ , ~ - ~ oi ) i s fiiitoiiiology -l~~:in11 1’l:tnt Quarailtine were augchlorophetiy1)-ethaiie (hereiiiaftc-r c d e i l iiiciitc~l by stmlie!; ;it II:irv:tr[l University, the I.-iii\ ei-5ity oi ~\I~ir>~l,iiicl, u i ( l thc Oliio State V i i i 1)I)’I-j iI), the major impurity beiiig the o,,‘)‘. 1) U I isomer, i- t r i c l i l o r o - ~ - o - c l i l ~ ~ r ~ ~ ~vcrsit?, ~ ~ i ~ ~uii(ler i ~ ! - ~:I- pro;i-~$iii - - ~ ~ - ’ ~ ~ ) O I I S C J I1T by the Oi‘tice oi Sciciitific 1Cescarc.h:mcI 1 )c\-eloi)iiient. Eecausc. clilorophenyletli~i~e (11) or tbc- c(JllliJl(ltC‘cO;’~I)?r:iti~ 111 alnollg these gr(xlp5, it W ~ L clwiiie~l -~ :td\-isabIe to presciit some of their ]I,/J’-
I
i~ii~!iiigs i i i t!ii, joint. r r i ) ( ~ r t . R 7 l i v ; i tlie exl):iii(leccss involved condensation of “chlorip. 10S.5-109.0° (cor.), and is intendetl a4 nated alcohol’’ and chlorobenzene. The method of standard of comparison for special phpiolvgicJ attack varied somewhat in the different laboraand pharmacological studies. tories; fractional crystallization antl chromatoInsecticidal preparations containing D D T i~ c I e graphic separations were employetl r t II lier genfirst brought to the attention of the United States erally by all, supplemented in one iiistance by Department of Agriculture in October, l i , 12, by cryoscopic malysis. Distillation in high vacuum the Geigy Co., Inc., New ‘Cork, S I’ It t l u t w . 1 ~thoroughly csplored as a means of separating time concerted efforts were being rnatlc bv the the by-product oil into its components. In the entomologists of the Bureau of Enturric,loq? ant1 espeririiciit:il section the separation of one of the Plaiit Quarantine t o find suitable substitutes for s:itnples is clescribeil in detail ; important deviapyrethrum and derrii, the imports ( J f tlic former rc:ttiiit,ii t ,,)ithe other samples arc being insufficient to meet wartime iieiiiairli antl the supply of the latter ha\ing bceii ~ o i i i p l e t ~ l v ned in the isolation of the compocurtailed since the fall of Singapre to the J.ipa- writs C J teclinicd ~ D D T are indicated in Table I. nese. The first entoinological twts 111 this couiitry as we!l ;is values for the p,P’-DDT content measwere made in October, 10 i2, aqiinst 3 nuiiiber ured by recrystallization from 7570 aqueous of leaf-eating insects. In S o x ciiibir test> were etliariol previously saturated with p,p’-DDT. made against thr body louic Some of the This nicthotl is reportctl“’ to give results accurate early results were publi\hecl ni F c h r u q , I O + 1. t o ivithiii I‘ i . (A1nnalicl,e/ ill ‘1 L-hi r i d 1 5 mere i o l i i o i i i The i-xcurrence of the fourteen compounds isu15lIlg th‘tt D D r l o ~ s cpo\?(le~TVA drbptetl 11: lnteil inay lx, rsplained from a consideration of the May, 1943, and utie coinpan\, wa5 requehtetl t o undertake the niatiufacture i ~ fI1I)T on ‘i suable niain :ml side reactions of chloral (and possible tt.chtiica1 chloral) and chlorobenzene scale. P ~ l o t - p l ~ iI)ro(ltiction ~it \vciq 1)cgiiri ti1 \CLtv, i‘ iiiipuritiLls iii technical chlorobeiiijreseiice of suliuric acid, followed by thc, pro(liict itiisturct with an alkaline < I
c~
THECIIEMICAL COMPOSITION OF TECHNICAL DDT
Sept., 1945
1593
TABLE I COMPOSITION OF TECHNICAL DDT Sample 1 (Setting point,
91.Z0), %
Compound
l-Trichloro-2,2-bis-(p-chlorophenyl)-ethane (p,P’-DDT)”
( a ) 66.7,
( b ) 72.9
l-Trichloro-2-o-chlorophenyl-2-p-chlorophe~~yletha11e (o,p‘-I)I)T)
19.0
l,l-Dichloro-2,2-bis-(p-chlorophenyl)-ethatic (p,p’-UDUJ (1.3 l,l-Dichloro-2-o-chloropheiiyl-2-~-chloroplie1iylet~~a11~ (o,p’-L)l>U) . . . . . . 2-Trichloro-I-o-chlorophenylethyl p-chlorobc~~zciiesulfoii~tc 0.4 2-Trichloro-1-p-chlorophenylethanol 0 2 Bis- (p-chlorophcny1)-sulfone 0 , (i a-Chloro-a-p-chlorophcnylacetamide ......
Sample 2 (Setting point,
88.6’), %
(h) (c) (d) (e)
70.5, 63.5,
(a) 72.7,
64.5, 07.9 (c, 7 . 9 , ( ( 1 ) 15.3, (P) 20.9 40 ,
....... 1.85
ti.5
74.8“
0.1P 0.044 0.57 ....... 0.0:34 0.006
...
....... .......
......
...... I).1’
11.96
....... .......
...... ...... I).02
...
(b) 76.7
......
~-~h~oro-~-o-c~~~orop~~clly~ac~tanlidc Chlorobci~zene p-Dichlorobenzcne 1,l ,1,2-Tetrachloro-2-p-chlorophc1iylethatlc Sodium p-chlorobenzcne-sulfonate .4inmonitiin p-chlorobenzene-sulfonate Inorganic Cnidcntified and losses
Sample 4 Sample 3 (Setting point, (By-product 91.4’), % oil), %
....... ....... .......
.......
0 .005
0.04~ 5.1
0.01h
10.6
... 0.11
... ... ...
... 2.44 0 ,i ; 3 +e
... ...
... 19.4
Letters i n parentheses refer to analytical methods as follows: (a) Isolation from technical DDT, ( b ) recrystallization from 7 5 7 , aqueous ethanol previously saturated with p$’-DDT (Cristol, Hayes and Hallcrlo), (c) fractional crystallization, ( d ) adsorption analysis and fractional crystallization, (e) isolation, supplemented by cryoscopic analysis on the residue. b This value does not represent all the o,p’-DDT present, as all oily fractions were not exhaustively studied, c hliscellarieous fractions containing p,p’-DDT, o,p’-DDT, and P,P’-DDD. Includes 0.06% of p,p’-DDD isolated as such and 0.11pCof the corresponding olefin. e Isolated as nitro derivative from an oil mixture analyzing for a mixture of Qualitative tests for ferric, lead and magnesium CsHsC], and CaHsClj and representing 2,54y9 of original material. Insoluble in boiling 955’0 ethanol. * Qualitative tests for fcrric, alnniotiiu~n,halide and car\)oiiatcs wcrc obtained. sulfate iotls were obtained. a
’
c1 ( ~ C H C I C O N H ~ XI .
2 CEHjCl
111
+ HC1+
I11 --+ HCl
C l ~ C H C I C C l ,
IX
+ C l ~ C H C l C O C --+ l “3
C I ~ C H C I C O N H ,x
+ CHCl?CHO +
XI11
All the compounds isolated from technical D D T have been tested as insecticides, as have the uncrystallizable oils. Although some of the byproducts are active insecticides, none of them are so toxic as P,p’-DDT.li Of the fourteen compounds isolated from the various samples of technical DDT, seven have been described in the previous literature. These include chlorobenzene, p-dichlorobenzene, p,p’D D T (I), 2-trichloro-p-chlorophenylethanol(III),
~
(10) Cristol. Hayes and Haller, 17, 470 (1945).
ZitJ.
Eiig. Ciiem.. A u a i .
Ad.,
(11) T h e entomolojiicnl testing of these compounds has heen cdr rietl oiit i n s e \ e r J Idboratorres of t h e Buredu of Entomology and
I’ldnt Qudrantine
1594
HALLER,BARTLETT,DRAKE,NEWMAN, EAKER,HAYES,KILMERAND MAGERLEIN Vol. 67
bis-(p-chloropheny1)-sulfone (VII) and the so-
tained by dehydrochlorination of o,p’-DDT and dium and ammonium salts of p-chlorobenzene- @,PI-DDD, and a-chloro-a-p-chlorophenylacetic sulfonic acid (VI). Chlorobenzene was identified acid. l-Trichloro-2-m-chlorophenyl-2-p-chloroby boiling point and conversion to p-nitrochloro- phenylethane (nz,p‘-DDT) and its olefin and dibenzene. 9-Dichlorobenzene was identified by nitro derivative are also described. its boiling point, melting point and mixed melting In the course of this work it was necessary to point. The structure of p,p‘-DDT was estab- prepare all of the six isomeric dichlorobenzophelished by degradation to p,p’-dichlorobenzophe- nones with one chlorine atom on each ring. Of none. The carbinol (111) was converted to its p- these, the o,p‘- and p,p’-dichlorobenzoplienones chlorobenzenesulfonate and this derivative was were already known. m,p’-Dichlorobenzopheidentical with the ester prepared from a known none was prepared by degradation of m,p’-DDT. sample of carbinol.I2 The sulfone (VII) was iden- o,m’- and nz,m‘-dichlorobenzophenones were pretified by a mixed melting point with an authentic pared by the addition of m-chlorophenylmagnespecimen and by conversion to its dinitro deriva- siuni bromide to the appropriate chlorobenzonitive.13 The cations of the salts of p-chloroben- trile. o,o’-Dichlorobenzophenone was prepared zenesulfonic acid were identified in the usual by oxidation of o,o ‘-dichlorobenzilic acid or bisfashion; the organic portion was identified by (o-chloropheny1)-carbinol. The acid was preconversion to p-chlorobenzenesulfonamide and pared by the reaction series, aldehyde, benzoin, the corresponding anilide. benzil, benzilic acid, starting with o-chloroThe remaining compounds isolated apparently benzaldehyde, and the carbinol was prepared by have not been described previously. The struc- the addition of o-chlorophenylmagnesium bromide ture of each of these was established by elemental to o-chlorobenzaldehyde. The preparation and analysis and degradation to known materials and properties of the 2,4.-dinitrophenylhydrazones of was confirmed by synthesis. the six isomeric dichlorobenzophenones are also o,p’-DDT (II), 1,l-dichloro-2,2-bis-(p-chloro- described. phenyl)-ethane (XII) and 1,l-dichloro-2-o-chloro- The recovery of known compounds in the samphenyl-2-p-chlorophenylethane (XIII) were de- ples varied from 80.6 to 93.5%. It should be graded to the corresponding dichlorobenzophe- noted that the recovery of by-product materials, nones and were synthesized by the condensation of notably the o,p’-DDT isomer, was probably not chlorobenzene with 2-trichloro-l-o-chlorophenyl- complete in all cases as in some samples all of the ethanol, 2,:!-dichloro- 1-#-chlorophenylethanol by-product oils were not exhaustively studied. and 2,2-dichloro-1-o-chlorophenylethanol,respec- Of the material listed as unidentified] a large part consisted of an uncrystallizable oil which tively. 2-Trichloro-l-o-chlorophenylethyl p-chloro- had total and hydrolyzable chlorine analyses benzenesulfonate was degraded to o-chlorobenzoic equivalent to that of a DDT isomer or isomers. acid and to p-chlorobenzenesulfonic acid and its Degradation of two of these oils to olefin by destructure was established by synthesis from 2- hydrochlorination and oxidation of the olefinic trichloro-l-o-chlorophenylethano114 and p-chloro- material with chromic anhydride did not lead to benzenesulfonyl chloride. the formation of any solid dichlorobenzophenones a-Chloro-a-p-chlorophenylacetamidewas de- other than PIP‘- and o,p‘-dichlorobenzophenone, graded to p-chlorobenzoic acid and to ammonia nor did nitration lead to isolation of new solid and was synthesized by ammonolysis of its acid nitro compounds. The evidence available sugchloride which was in turn prepared by the reac- gests that these oils were mixtures of D D T isotion of phosphorus pentachloride on p-chloroman- mers. delic acid. The corresponding o-amide, which In the case of sample 2 (Table I) the amounts was not isolated in pure state, was synthesized of p,p’DDT and o,p’-DDT in the oil and oily from o-chloromandelic acid in a similar fashion. solid remaining from the fractional crystalliza1,1,1,2-Tetrachloro-2-p-chlorophenylethane was tion were estimated cryoscopically. A general not isolated in pure state, but the nitro derivative method for determining the composition of a mixof isolated material was shown to be identical with ture is the determination of the freezing point the nitro derivative of the synthetic material ob- depression produced by that mixture in a series tained by the action of phosphorus pentachloride of solvents known or suspected to be components on 2-trichloro-1-p-chlorophenylethanol. of the mixture. If 1 g. of a mixture of A, B and C The details of the isolation and synthesis of is dissolved in a known weight of the solvent X, these compounds are given in the experimental which is not a component of the mixture, the section. Also included in the experimental section freezing point depression gives directly m, the are descriptions of a number of compounds pre- total number of moles in a gram of the mixture. pared either as derivatives or intermediates in the On the other hand, if the same mixture is dissolved synthesis of the isolated compounds. These in- in pure A, the freezing point depression gives the clude the dinitro derivatives and the olefins ob- total number of moles per gram which is not A, (12) Howard, T H I S JOURNAL, 61. 2317 (1‘38.5). i.e., m - u. The difference between these two (13) Ullmann and Korselt, Ber., 40, 043 (1907). figures is a, the number uf moles of -4 in 1 g. of the ( 1 4 ) FIoaard and Castles. THISJ O U N N A L , 6 1 , 37G (1035).
THECHEMICAL COMPOSITION OF TECHNICAL DDT
Sept., 1945
1595
2 ethanol recrystn.
Insoluble inorganic material 8.50 g.
hlother liquors
p,p’-DDT 5430 g.
!
.1
3.
Oil B
Solid A
3. recrystn. p,p’-DDT o,p’-DDT Oil A-1
310 g. 1070 g. 12Og.
+I
oii, c I Pentane pptri
Solid B-1 Pentane recrystn. p,p’DDT 35g. o,P’-DDT 185g. Oil B-1.1 41 g. (ClCsHr)2SOz 2.6 g.
.1
/----------I
4 ?lid C-1
Pentane recrystn. 140 g. Oil C-1.1
(clca,)zso2
CIC&SOaNa
48 g . 47 g. 1 . 8g .
4
Oil D Chromatographic analysis, m i x . P,P’-DDT o,p’-DDT P,P’-DDD 011s
(cIca4)zso2
CirHpO.XlsS ClCaHiCHOHCCli
mixture. In principle this iiiethod xxay be applied repe;tedly for each component of the mixture, but a practical limit to its application is set by the difficulty of determining accurately a small difference between two large numbers. The method is therefore useful only for components present in substantial amounts. A recent precise application of this method is described by Streiff and R 0 s ~ i n i . l ~ By application of this method an oil comprising l6.8Y0 of sample 2 was found to contain 13y0of p,p’-DDT and 43% of o,p’-DDT, and a crude, oily solid, representing 11.6% of sample 2, was found to contain 19% of p,$’-DDT and 49% of o,p’-DDT. ‘This indicates 4.4y0 and 13.0%, respectively, of these two isomers in the original sample in addition to the amounts isolated directly by fractional crystallization. All except about 5y0of sample 2 was thus accounted for. ’
Experimental Separation of Technical DDT The separation procedure described below is sunimarized in Chart 1. Nine kilograms of a sample of technical UDT was rccrystallized twice from 95% ethanol (7.5 liters of solvent per kilogram of techiiical DDT). There was obtainccl directly 5.43 kg. of p,p’-DDT,la 111. p. 107108’ (cor.). Furthcr recrystallization from ethailol or ligroin gave a product ~neltinga t 108.5-109.0” (cor.). The structure of p,p’-DI)T was confirmed by dchydro(15) Streiff and Rossini, J . Xeierirch Karl. Btrr. Sfafrdards, (1944). ( 1 6 ) Zeidler, Bcr., I , 1180 (1871).
S¶, 185
20 g. 340 g.
35 g. 329 g. 5.6g. 33.4g. 21.6g.
chloririatiou wit ti cthauolic potassium hydroxide to I , 1dichloro-2,2-bis-(p-chlorophenyl)-ethylenc,ni. p. 88-89” (cor.) aud by oxidation of this compound with chromic anhydride in glacial acetic acid to p,p’-dic,hlorobcnzophenone, which melted alone and when iniscd with a n authentic sample, a t 146.5-147.5’ (cor.).li Concentration of the mother liquors gave about 1.5 kg. of a solid fraction (solid A on chart I ) , which melted a t 54-68‘, and about 1.4 kg. of a red-browii oil, B. Fractional crystallization of solid A from ir-peiitane gave 310 g. of p,p’-DDT and 1070 g. of o,p’-DDT. The latter compound, l-trichloro-2-o-chlorophe1iyl-2-p-chloro~heny~etliane, which has not been previously descrilwd, Ineltrd after recrystallization from methanol a t 74.0-i4.5 O (cor.). Anal. Calcd. for ClrHpClj: C, 4i.43; H, 2.56; C1, 50.01. Found: C, 4i.35; H, 2.64; C1,49.84, 50.03. The structure of this product was proved by dehydrochlorination to the corresponding I,l-dichloro-2-o-chlorophenyl-2-p-chlorophenylethylenenieltiiig a t 78.4-i9.5’ (cor.), and oxidation of this product with chromic anhydride t o the known o,p’-dichlorobcnzophcnone, which melted, alone and when mixed with an authentic sample, at 64.2-65.2’ (cor.). The melting point of the isolated o,p’-DDT was not depressed when a sample was mixed with a sample prepared by the condensation of 2-trichloroI-o-chlorophenylethanol with chloro$ciizene. Upon nitration with fuming nitric acid a t 50 , o,p’-DDT gave a dinitro derivative which, after recrystallization from 95y0 ethanol, melted a t 148-148.5” (cor.). Separation of p,p’-DDT from o,p’-DDT in n-pentane was aided by the fact that p,p‘-Dll’r crystallized in soft needles or clusters whereas o,p‘-DDT crystallized in hard rhombs. In addition t o t h c solid fractions iaolatcd ill this frac(17) After this work lind been completed and while this report wus in preparation. proof of this structure was reported by Grummitt Buck and Jenkins.“ (18) Grummitt, Buck nnd Jenkins, THIS JOURNAL, 61, 155 (11)45),
Chroaatograpliic >eparation I
II
Pentane fractionatloti
j.
Ci,HqO?CI,S 0.13 g . I
.tioriatio~i,there was 120 g . of oil A-1 (rtz5u1.CilZJ. 'l'hia oil, upon dehydrochlorination and oxidation, gave a benzophenone mixture from which 50% of p,p'-dichlorobenzophcnone was separated, indicating that at least 60 g. of this oil was probably p,p'-DDT. Oil B slowly dcposited crystalline material. After standiug for several wceks in a refrigerator, the mixture rvas filtered, and the separated solid was washed with cold ri-pentane. This solid (B-l), in. p. 88-72', represented 207; of oil B. Crystallization of this solid fraction from ?i-pentane gave 3 5 g. of p,p'-DDT, 185 g. of o,p'-DDT, 41 g. of oil B-1.1 in% 1.612), and 2.6 g. of his-(p-chlorophenyl)-sulfone, in. p. and mixed m. p. 148-149' (cor.); tiinitro derivative,13ni. p. and mixed m. p. 201-202" (cor.). Oil C, the filtrate from solid R-1, was treated with twice its wcight of n-pentane and placed in a refrigerator. After a week the precipitated solid was separated by filtration, vielding solid C-1. After removal of thc solvent by distillation, oil D resulted. Solid C-1 yielded 1.8 g. of an ether-insoluble, water,olublr solid. This solid gave a sodium flame tcst and Ivft a basic ash upon ignition. A qualitative test (after >odium fusion) indicated the prescnce of organic chlorine and sulfur. Treatment of the solid with phosphorus pentachloride, followed by treatment with concentrated aqueous amniotiia gave p-chlorobenzenesulfonamide, 111. 1). and mixed in. p. 144-145' (cor.). The anilide was also prepared in thc usual fashion, in. p. 103-104°.'8 This solid was therefore sodium p-chlorobenzenesulfonate. The remainder of C-1 upon recrystallization from npentane gave -17 g. of 1,is-(p-chloropheny1)-sulfone,141) g. of p,p'-DDT, 12U g. of o,p'-IlI>T atiti 48 g. of oil C-1.1 '7Zz5D 1.612j. 'l'hc fractioii of oil I) is outlined on chart 2. As oil 11 did not deposit any solid upon standing with i)cntane ill a refrigerator, an aliqaot portion was submitted to adsorption analysis. -4 10.00-g. sanlplc (total material TO5 g.) was dissolved i n 25 rnl. of carbon tetrachloride and subjected to adsorption 011 an activated alumina column 31 by 200 mni. and clutcd as follows, 100 ml. of iluting solvent Ixing used for each fraction: Fraction
I)-1 D-2
u-8
11-4 D-5
E l u t i n g solvent
Carbon t trachloride Carbon , trachloride
7.52 0.30
.I
"Q
lienzene I ~ c t t z c n eaiid
.570ethanol
:\bsolutc etliaiiol
i l l ) ) Wallach a n d H u t t i , N c r
Residue, 6 .
,
9. 420 11871;~
e>
.IS !\I)
Fraction U-l upon rcct-ystallizatioii froin Lwiitxtic gave U.25 g. of p,p'-DDT, 3.21 g. of o,p'-DDT, and 4.Ofi g. of oil D-1 (?t% 1.613). Although no more solid coiil~il i t isolated from oil D-1, nitration gave a misturc containing 2:3(,: of dinitro-o,p'-DDT, and oxidation of thc deliydrochlorinated product gavc a tracc of p,p'-die!iloroheiizophenone. Fraction D-2 was an oil ( ) t % 1.615) which could not be made to crystallize. Fraction 11-3,upon rccrystallization from pcntaiie, gave 0.31 g. of solid, i n . p. aftcr scvcral recrystallizations from 95% ethanol 109.5-110°(cor.). The analysis iridicateti that this compound was a tetrachlorodiphenylcthane. Anal. Calcd. for ClrHl&14; C1, 41.32. Found: Ci. 44.66.
Oxidation with chromic anhydride after dehydrochlorination gave p,p'-dichlorobenzophenone. These data suggested that this compoutid was l,l-dichloro-2,2-bis-(pchloropheny1)-ethane (hereinafter called p,p'-DDD), which might arise in technical D D T from an impurity of dichloroacetaldehyde in the starting chloral. The isolated conipound did not depress the melting point of saniplcs synthesized from dichloroacetaldehyde and chlorobenas zeiieZo or from 2,2-dichloro-l-p-chlorophenylethatiol, described in a later section. Identical dinitro derivatives, ni. p. and mixed m. p. 178-179" (cor.), were obtained from the isolated material and the synthetic material upon treatment with fuinitig nitric acid a t 50" and recrystallizatioii from 9,5ycethanol. The residual portion from fraction D-3 was an oil, D-3.1 (nZ51)1.607j, which did not crystallize and !vas iiot further investigated. Fraction 1)-4 crystallized upon removal of thc solvcnt and was rccrystallized from 95y0 ethanol, 111. 1). lO(i.9107.4" (cor.). The product depressed the m v l t i n g poiiits of fi,p'-IIl-)T aiid p,p'-DUU. It was soluble i l l etlier atid insoluble i l l \ r a t c ~ .dilute alkali or acid, and coticiiitrateti sulfuric acid; it \\.ISstable to boiling for fourtccti Iiours with 10% aqucou- i)otassium hydrosidc; it did i i u t distill at 250" (1 I I I I I I . I . A n elemental analysis indicatetl t h c fortnula Girl IPO~CI,,S. :l77uL. Calcd. for C14HoOaClsS:C , 3S.60; 11, 2 , 0 ! ) : CI, 40.80; S, 7.38. Found: C, 38.82, 38.91; K , 2 . 4 \ , 2.4s; C1, 40.43, 40.65;s, 7.20. Treatment of this material with ethanolic alkali gavc a water-soluble acidic material, which was shown to bc p-chlorobenzencsulfonic acid by conversion of its sodiuiii salt tl~roughthe acid chloride to p-chlorohenzciir.su1foti..
. . ..
(20) This sainplc was k i n d l y supplied by H. S. hloslier. ol tht t ' ~ n u s y I v a n iS~t a t e Collrxe.
Sept., 1945
THE CHEMICAL COMPOSITION OF TECHNICAL DDT
1597
amide, ni. p. and mixed m. p. with an authentic specimen lent. Alkaline hydrolysis gave a steam-distillable base 144-146 '. The oil-soluble material separated from alkali which was shown to be ammonia by the preparation of treatment was oxidized with alkaline permanganate to a benzamide (identified by melting point and mixed meltacidic material, which upon recrysta1liz:tion from water ing point) from i t by standard procedures. The foregoing data suggested a-chloro-a-p-chlorophenylgave long, white prisms, m . p. 130-139 . This behavior acetamide as the only reasonable structure for this coniwas suggestive of o-chlorobenzoic acid (m. p. 142'). The isolation of these two materials indicated that the pound. This was confirmed by synthesis of this comCIaHs03C163 compound was the p-chlorobenzenesulfonate pound by ammonolysis of the acid chloride prepared by of 2-trichloro-1-o-chlorophenylethanol.This compound the action of phosphorus pentachloride on p-chlorowas shown to be identical with synthetic 2-trichloro-l-o- mandelic acid. The melting point of the isolated material was not depressed by the synthetic material. chlorophenylethyl p-chlorobenzenesulfonate. In connection with this compound, the corrcspoiiding Fraction D-5 was fractionally crystallized from etherpentane solution, giving 70 mg. of bis-(p-chloropheny1)- acid, a-chloro-a-p-chlorophenylacetieacid, was syuthesulfone and 294 mg. of 2-trichloro-l-~-chlorophenylethyl sized by hydrolysis of the acid chloride. This acid melted p-chlorobenzenesulfonate. The residual oil was distilled a t 75-76' and had the correct analysis for carbon, hydroa t 1 nim. in a vacuum sublimation apparatus. The dis- gen, and chlorine. v. Walther and RaetzeZ2have reported tillate, b. p . 140-170" (bath temperaturc), was a mobile the synthesis of this substance by the action of boiling oil :nZ5Dl.t580) weighing 270 ing. I t gave a positive test concentrated hydrochloric acid on p-chloromandelonitrile. for the CCl,is." Vol. 2 , \'sin Nostrand Co., New York, N. Y . , 1937, p. 3fiO
\V;iltlier a n d I
