Document 6BZp55J95djZYOa1LDebd3g43
?::<
WKINUAHTKN
vol, 26
] 1/..11 ini, l linminlogriipliy of I g. of tins miMllleoli alumina9'
in*I '1'iiiim with 1'tlii`r timl mellivli'iic chloride gave 11.75 g.
ui VI.
172 178 followed by '5 <1.18 (4. of VII. m.p.
lx I I Vi Tim* '21 H. of (.hu mixture has roughly 1:1 eoui-
(luMiimi hi VI ami VII giving :m estimated lift yii'lil of 15.0
g. 87', of VII ami 18 g. M8%) of VI. Tim rcnmihing mule
r' :o'iion |iroiliirl was I'hrimmliigruphfd to iililnil) ti 8. of ft li't'ial, niiieh lacked Oil ami C KMI bunds linfriired)
n.'i ' !:* .a la I .-a i iir.-i i i'll ami u,,Tiiimaliiralcil ciirliooyl bands,
rin- linhnl lia.- mil In-i-u further examined.
\\ lolo I g. of jniri* \'ll I'oiilil Im uliiiiini'iI from -1.2 g. f
VI i.imIit conditions described In (I,), tlm -(iir(inti matorinl .a- riTiiu'ml nuelumgcd when ilhniiol wn* omitted in
.m<>( her i'v|>i-riiiii'n(. Wlicn I g. of 17,>-i'thynyl(i,stosli'rime,,<i
iii.p. '-'ill 211(1. wn* Iri'nli'il ns in (li) tlm. starling nmtorial
a. ri'i'oviTi'il imit mi i k< .
A'/o,ior/ziitintt nf VII In VI. TmiliimnI of 2.10 a. of pure
VII, m.|i. IM 185, ns in (li) above yii'lilcil 0.4 g, (18.5`7o)
of VI, in,p 172 178, and I .5 g, (HIM' |,l nf VI I, in,|i, 184-
|.V>. in- i-ry.-ialli/.iitinn ami chromatography.
l.l'.)ltini!il-ln.6~`liiirvliixy-3U'iHithiil-l ,3,3,7,8,8il-kextlliytlro-
iitilihllrilt ni, I\\ Tri'alini'iil of 2.8 g. nl VII, ni.p. 181-185,
at room trinimraluri' with 15 nil. of noetic anhydride con-
lainiug IIH) mg. of /,-tolncucsnlfnnii' m'iii yidili'il 2.11 g. of
priiilitrl, ni.p. Ill) 111- tiflcr a work up ns almvo. One
crystallization from ether-pel rnleinn ether tli.p. ;I5-55i
afforded l.s g. (57i.I' J) of l.V, ui.|i, 11:1-11-1; \aat 284 mg
< HI.H5II); infriireil M.llt (s), LSI) t\vi, 5.70 (*). 5.70 (s), ii.lM) mi, 0.10 iini g.
1 mil. (ailcil. lot (5,11.1,1),: (', 70,8; II, 7.0. found:
`. TI 0, 71.0; II, 7.(1, 7,1.
I 'niiin.iiiih nf IX In I. \ aolnl ion of 1.18 g. of IX in 5 nil.
of till'; fomiic arid was refluxed for 1.5 hr. mnl work'd! n|>
as il''.-i'rilii'il in iIn* preparation of 1 from VIII. Cliroinalng-
rnpliy of the crinli' lapiiil yielded 881) mg. /82.li,,;.'l of I,
m.p. ami mixed in p. aitli proiloct from VIII. 07-08
21 Wlmii iIm I'limnmri'inl iiciilral Alnniiniun i iv'uliWiii-hn m." ii'ial, i'\li'ii-ivi' his* thin In di'i'onipnsiliuu ticrnrri'il.
- --i Aicoriliiig lo tlm generalization of D. II. H. Iliirlini ami l(. I'. Ciioksou, (Jiiurl. Hen., 10, 41 (IPoli) tin* etliynvl ah'ohol. m.]i. 172-178. chip'll lir.il, should liavu an axial hydroxyl group. This assignment wniilil imlicali' slriicture \'1I lor llm 172 isomer ns proposial hy Xazarov.11 However, as fiii'lors responsible fur iiilsorpliiin of the epimerie alcohols, VI mnl VII, might Im complicated by the proximity of the "nHiii.-ntnruU'il rarhoiiyl funcliun, a ilofiniti! iissigiiincnt l aniiol he mailo without, fnrtlii'r evidence, Wo have preferred ilie structures given for reasons nienlioiH'd.19
(2ti) Wo wish (o (hank tin: Upjohn do., Kalamnzoo, Midi., for tills sample.
l-Acelyl-6-oxo-8a-melhyl-3..'.U, 7,8,Sa-l\exahydronuph-
lluilcnr-fi-lriinelhytentlhiokelal, X. To n suspension of 1.8 y.
of I in a mixture of 5 ml. of ether and 2 ml. of boron flnoride-
ethornte cooled in ice hath, I ml. of propnne-!,8-ilithiol wne
willed dropwitso, The suspension soon turned to a clour "illa
tion and in 2 hr. nut to a muss of needles. The mixture was
dissolved in ether, washed with 10% niiueons amliitm Idcnr-
Imniile nliil fronted ns usual, The crude liquid deposited 2.2 g,
nf `crystals which ott reerystiillmUiun from ether nflonled
2.0 g. (75%) of X, m.p. 110.5-120.11;
280 mg (<
12,800)"; infrnrcil 11.00 (s). 0,18 (in) g built of relatively
diminished intensity ns compared to same iienks in I.
,4 nal, Onlnd. for CVHwOSi; O, 05.8; H, 7.5; S, 21.8.
Pound*: d, 05.1. 05.8; II. 7.0, 7.0; rt, 21.(1, 21.8.
I-A ciliil-68-li>jdriixy-8a-melltyl-3,4,6,7,8,8ii-hexnhijdronaph-
Ihalene. XI. A solntior, of I g. (5.(1 mmoles) of I, 200 mg.
(5.8 mmoles) of sndlnm Iturnhydride and l ml, of water in
10 ml. of Miutyl alcohol mis stirred for I hr. nl room fem-
pcralure. Tlie excess Imrohyilridi' was destroyed by adding
a few drops nf glacial acetic arid and the mixture evMpnriitcd
lo dryness. After the usual treatment the crude Hiptiil gave
0.5 g. if crystals, m.p. 111-114, and the mother liquor
on chromatography ulTorilcd a further 120 mg. ef crystals.
Two crystallizations from elher-au'tlmnol yielded 0.68 g.
(58%) of ettlurless XT. m.p. 115-117, hm 281 mg (e
11,001))"; infrared 2.80 (s), 0.08 (s), (5.10 (m).
Anal, (.`tiled, for dnHnO,: d, 75.7; H, 8.8. found*:
O, 75.8, 75.8; II. 8.0. 0.0.
('nnw.u'nn n/' I lo Xtll. To a snlntioii of 1.1 g. of I ill 10
ini. of dry methanol was added 0.18 g. of sodium hydroxide.
The initially colorless sohilioit lurnt'd dark ml inst.anlnito-
otisly on adding the alknli. After 12 hr. at room tempern-
lurn, the reaction mixture was nridilicd with a few drops of
glacial acetic acid and evaporated to dryness under aspirator
pressure. The residue dissolved in methylene ehlorid" ivaa
treated as usual. Tito crude liquid was chromatographed on
alumina ami eluted with 1:1 cllior-hcuzcnc mixture to ob
tain 11)1) mg. of crystals, m.p. 115.0-110.5. Charcoal Iront-
nu'iit of an ether sulutiuii furnished 870 my. (88.0%) of
colorless XIII, m.p. 110-1)7; ,\o,a 2711 tag u 25,000);
infrared 5.82 fs). 0.02 (s). 0,14 (v.s.), 0.20 (s) g,
.inn/, ruled, for OnHi',0.,: C, 70.4; H, 7.0. found';
d, 70.8, 70.4; II, 7.7, 7.0.
doi.UMBt'.s III, Omit Madras 25, India
(27) We helieve that the methyl ketonic fiinetion is free
in .X for two reasons: (u) tho absorption tnnxinium for XIV,
VI, and VII is at 242 mg; (li) the
for t-ueetyM-cyclo-
lii'.xetu1 tvpes is at 282 nig, Sec J. II. ('Inuilcv. J. Am.
Client. Site., 70, 244 (1048).
'
|('o.xTiuncrxo.\ from iiib Research and EnqiNderi.no Division, Mon.naxto Chemical do.] / I
! Slerlc Effects in the Gomberg Keuction1 .
HAROLD WKIXGARTEK
Ui
lieccived June 10, 1060
The inllm'iice of substitution urlho to Uin radical site in homolylic tiromalio arylnllon wan investigated. Sterio elleota wore found to be uiiiguitieaui.
Although llte Gomberg reaction lius been known in the literature4 for nearly forty years, it has
(I) Presented at- the I35tli Meeting of tho American Chemical Snch'lv at Boston, Mnss,, April 1950, Abstr., p. 47-D.
been investigated quantitatively only daring the last ten.8 The bulk of these quantitative studies describe tho ratio of biphenyl products
(2) M. Gomberg and W, E, Bachniun, /. Am. Chtn. Sac., 46, 2839 (1024),
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MAItCII 11)61
STEUIC EFFECTS IN THE dOMUERO REACTION
731
derived from the phenylation of substituted aro phenyls cun be formed. The experimental results
matic! solvents. A number of studies have also are recorded in Table I.7 *
been reported in which para-substituted phenyl Phenyl and p-chlnrophenyl radicals were used ns
radicals wore used rather than phenyl radicals.34>5 controls (Reactions 1 and 2) and found not lo
liven fewer quantitative studies have been re vnry significantly in product ratio from each other.
ported describing the effect, of substitution ortho to Furthermore, their o/p ratio agrees witli that, re
the radical site.6 In the present work we report the corded for tlxo phenylation of chlorobenzene, *9
behavior of several ortho-substituted phenyl radi orf/io-Cldoro and orffm-bromo substitution are
cals. The results of this study have enabled ns to seen t.o lower measurably the o/p ratio (Reactions
describe the configuration of the product deter 3 and 4) while c-methyl substitution (Reaction 5)
mining transition state in somewhat, more detail. remains at. the control vnlue. These results have, led
us to the conclusion (lint, while wf/m-hnlo substitu
IcESITjTS
tion may give rise to unfavorable dipolar repul sions in tbe transition slate, sterie effects are rela
The influence of substitution ortho to the radical tively unimportant-.
silo was investigated by generating oW/io-substi- To eon vinee ourselves of I lie lack of importance
tuted phenyl radicals in the presence of o-diehloro- of sterie effects several experiments were carried
bonzene. The use of o-diehlorobenzene greatly out with m-diehlorohenzene (Table TTi. A eont.rol
simplified the product analysis since only two bi experiment with phenyl radicals revealed an o,o'o,p
ratio equivalent to that. obtained with o-diehloro-
TABLE I 0 -DICHLDROBENZENE RESULTS
benzene in close adherence to the principle of ad ditivity. The use of o-methylphenyl radicals showed
a small sterie effect, hut even hero the o.o-position
is the most reactive, Orf/io-ehloro substit ill ion causes
a more marked decrease in 0,0-produet as would be
expeeled.
TABLE D
2.-D!CHl0R08ENZENE RESULTS
% o,o %o&
%m,m
(3) D. H. Hey and G, U, Williams, Discussions Faraday Soc., 14, 210 (1953),
(4) C. Shill, D. H. Hey, and G, H, Williams, J, Chew. Soc., 4403 (1958).
(5) It. L, Daimley and M, Slernfcld, J, /1m, Chan. Soc., 76, 4543 (1954).
(0) D. H. Hey, in Theoretical Organic Chemistry--The Kekute Symposium, Buttcrworths, London, 1959, p. 257.
(7) The laboratory method we used to genornto phenyl arid substituted plumyl radicals involved treutrnent of the
diazonlum chloride with sodium acclalu. Yields were be tween 30 and 00%. Wo do not feel these low yields rcUect a fractionation of products or preproduct intermediates since the work of D. !', DeTur and H, J. Solteifclo, Jr., J. Am. Chem. Soc., 73, 1442 (1951); R. Uuisgen and It, Grushey, Ann., 607, 49 (1957); D, R, Angood, D. H. Huy, and G. If. WilliumH, J. Chem. Soc., 2004 (1952); nnd D. H, Hoy, A. Nuchvatnl, nnd T. S. Robinson, J. Chem. Soc., 2802 (1951) demonstrates that biphenyl product ratios are nearly unchanged over a yield range between J5 to above 80% using various radical sources under a wido range of conditions. Nevertheless, it Bhould lie pointed out that the ArAr'H. intermediate has been Bhown by D. I''. DeTur and R. A. Long, J. Am. Chem. Soc., 80, 4742 (1958) to yield products other than biphenyls wltere Ar'H is uosubstituted.
Product structural assignments were mndc by one of three methods depending on the compound; (1) independent, synthesis, (2) isolation from the reaction mixture followed by oxidation to the sub stituted benzoic acids, nnd (3) comparison of struc ture to relative vapor phase chromatographic re tention time9 (para isomers always had higher retention times than ortho). The products of Re action 1 (Tnble I), 2,3-(orlho) and 3,4-dichlorobiphenyi (para), were independently synthesized and the para isomer shown lo have the higher retention time. Two crystalline compounds were isolated from the product- of Reaction 2. Oxida
te) R. Huisgcn and R. Graahey, Ann., 607, 4f ''1957). (9) Gns chromatography was our principal u.i.'.vocal tool and the chromatographic areas were shown lo no pro portional lo mole per cent.
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WKlN'UAIlTtJN
VOL. 26
TA1I1.K 111 Ull'IlZXVL, 1 HlmVATIVHK
('(impound
M,l', (hit. M.I'ii
Carlion, % Fmunl Ciilcd.
_ Hydrogen, Foiimi ('nil'll.
Halogen, % Cnlcd,
2.0-1 Orhhirobiphcnyh' 0, l-Dirlibirohiphcnyb
thdilnrohiphcnyh1 0.5-1 liclihiniluphonyh1 2,0.1 '-Trirlibm>biphcnylJ 0. l, t `-'i'rii'lihtml iij)ln'Hy 1,( 'J.O.O'-Trii'hliimhiphi.'iiyl' 0, I.2'-Tiirlilun>hipheny l<
0,4-1 iii'tilorn-'J'-l irimiul >1]>I iciiyl3
27 7-28.2 18 0-19 (1 (TtS''> 24.1-21.1 :ii.tb;l2 o pltiM 78 0-711.2 SO,8-87 8 28.1-28.8 00.1-00.4 (011/)
00.0-60.5
04.5
04.7
55.7 50.2 55 9 55.0
47.0
01.0
04.0
50.0 50.0 50.0 50 0
47.7
0.7 0.0
0.0 0.0
2.7 2.7 0.2 2.7 2.7 2.7 2 S 2.7
2.5 2 ;l
01 8
01.0
41.1 41,0 41.2 41.0 in. i*i).
01.8
01.8
41 0 41 0 II .0 41 .0
4 lnil<'|ii'inl<'iitly synthesized cm (lomberg reaeliim. h W, lihikely ami II. A. Sriirhuvimgh, ./. f'hem. .Sac., I1(1117 ( 1927). * I.. K. Ilinki'l ami II. II. llov,./. Clirm. Nor., 276(1 (1928). J Isolated (rum Reaction 2, Table I. Isolated frimi Ueaclinn 0. Tnblo I. ' I- Miisrari'lli, 1). (InUi, ami 11. Dingo. (Inn., 63, 054 (lllllll). 11 Isolated from Hoai llim 4, Table I.
limi id' (lie emnptment with 1 he higher retention
lime yielded n mix!lire of IM-dieldornlienzoic mid
hliirobeiiznie acids proving it to lie I lie pnni
.liner. In ti similar way the component with the
Higher l'elenlion timi: was shown to be (he para
isomer in Relictions li mu! 4, liy analogy wit it t he
preceding examples the component with die
higher retention time from React ion "> was assumed
to he the para isomer.
Tile prodoels of Reaction 1 (Table III me 2.(1-
dieldorohipiienyl (o,<n, 2.4-diehlorolii]ihenyl te.pi,
and .'i.o-dirhloroliiphenyl (nipin. 2,4- .mid ,'i,5-l)i-
eiiloroliiplienyl were indepeiideinly synthesized and
used to assign slmclnres to the ehromatographie
peaks. The siniel-ural assignments for Read ions 2 In this transition stale die carbon-halogen dipoles
and d were made hy iinalogy with Ueaelioii ].
are able to internet, while sterie pressures between
the substituent groups are minimal. The substit
mseisstox
uent .V is pictured as being away from the o-
Allhmith il has been suggested 1.1ml- bond fonnati<hi in (he transition st.ate has progressed almost, to .s/d hybridization,1" we consider this hypothesis Untenable. The lack of coiitrnsl. shown in (lotnliorg
dieiilornhenzene ring since an examination of models shows significant sterie repulsions are pos sible between X and the ring if II ami X arc inter changed.
read ion relative rules, parlieularly (lie factor of only twenty-fold between benzene and naph
t'.xrrauMiJN'TAiJ-
thalene,1' and the high proportion of mdn- sub diiiHhcrd n'urtinn. Oeiirrnl mlliotl. Td 0.1 mole, of aniline stitution argue strongly for a long, "7r-lrkc" Imnd or substituted aniline was milled .JO nil. of coned, hydro
in the iransition state. Furthermore, ihe transition stale picture must permit us to rationalize the dipolar repulsions we believe we have observed and the lack of significant sterie elTects. The transition state most consistent with the above rci|Uircmonis is described in Fig. 1. in this representation the direction of the forming ('--C bond is nearly perpendienlar to the plane of the o-dirhlorobonzcne ring, The plane of the radical bearing ring
chloric licit! and the mixture was cnnlcd in an ice Imlh. To this mixture was slowly aihleil a solution of 111 g. (0.(5 mole) of sodium nitrile in 15 ml, of water, keeping die temperature Ili'liiW 5. If ill! of the solid dill not dissolve il was littered out liefuru the next- step, This solution of diazimium suit wua lidded to OtH) ml. of enld soivcid-snbstrnle (o- or m-diehtnro-
beuzniir or licnzene) with vigorous stirring, followed liy the addition of an ai|iieoiis solution of 51) g. of sodium nectate. trihydrntr. The ire hath was removed nnd the reaction mix ture allowed to stir at room temperature mail the evolution of nitrogen subsided. The Icmpcrnlure of Ihe reaction was
approximately bisects the iMlielilorahenzene ring gradually mien! until no more nitrogen was evolved, Be
at tin* carbon to which it is becoming at inched. tween 90 and 100%, of the theoretical nitrogen was collected.
Tite direct inn of the 0--II bond at the carbon
Tim organic phase was washed Beverul times villi water, dried over magnesium sulfide, and the excess of solvent
undergoing substitution is only slightly modified.* 11removed hy reduced pressure distillation. The desired prod
uct w'ns collected by distillation through a simple Claisen
(10) D. It, Augooil nail 0. II. Williams, Chcm. Hers., 57,
18tl (1957). (11) II. lluisgen arul (1. Purer, Jim., 566, 162 (1050).
(12) Melting points are corrected, Analyses ro per formed liy the Analytical department, .Monsanto (. hi-mical Co., Dayton, Ohio.
STLCOPCB0003582 WATER PCB-SD0000054548
MAIilM 1901
(HOI)O-p'-SmtOllKNZUVl. PMtoXIDK
700
distilling head. Tho product was analyzed by gas chro matography without further purilienthm. Yields were generally between Oil uud 00%. Tuhlu III summarizes tho analyses and molting points of tho biphenyl products.
Vapor phase chronutlopraphic method, Tlio gas ehromntngrujiliy was curried out with either u Porkiu-Ehnor Modul I54C or a l'yo Argon iiiatnmunit, Tho l'urkin-Klmcr was ei|tii|ipeil with a 2-m. stainless steel tolttmn packed with lire brick C-22 (mesh 40-00) impregnated with Dow Corning Silicone Fluid 550 (10%). The eluent wus helium and tho column tomperoturo was in the range of 180-200. Tho I'yc Argon was equipped with a 4.5-foot column packed with ('elite (mesh 80-100) impregnated with How Corning Silirom* Fluid 550 (5%), The eluent was argon and the column temperature was in the range of 150-100.
Oxidation of biphenyl derivatives, (Jenerol method. One gram
of biy'.cnyl derivative wus dissolved in 20 ml. of noetic acid ,..). Three grams of chromic anhydride was added to a solution of 1 ml. of water in 20 ml. of acetic acid. Tintwo preparations were combined and heated on a steam hath for 2 hr. The react lull mixture was (lien poured into excess ice water aial the precipitate collected and lecryslaHizcd from benzene, The benzoic acid product was then Idem Hied by mixed melting jxrint with aullienlie sample or by inirarud analysis.
Acknowledgment. Tlio author wishes to thank Will lain D. Ross ami James IW. Scldiiter for llteii' excellent, work on tho gas elirimiutogrnphie analy ses.
Dayton, Omii
ICoNTiiinuTKiN ruu.u tub Dupautment or CiittMisvuY, Fi.niunA Statu I.'nivkiixityI
o-Iodo-jp'-nitrobunzoyl Peroxide1 2
WOLFGAXG HOXSUEUG and J. E. LKFFLEIt Ileeeived Jane IS, 1UBO
Uis(o-iodoheazoyl) jiuro.vidc nud o-iodo-p'-ailrohenzoyl peroxide decompose by a concerted free radical mechanism leading In heterocyclic lode radicals. The change from an o'-iodo to a p'-uitro suhstiluuiil markedly decelerates the decom position rather Until nreelemling it tm would lie expected for an ionic mechanism. The decniapusitiim of a-indo-p'-iiilmbenznyl peroxide is not subject to neid catalysis but. is accelerated to an unusual extent by polar solvents. Vinyl chain poly merization is initialed by the peroxide even in polar solvents.
Tho decomposition of his(o-iodobenzoyl) per
oxide (I) is a last, rettrl.inn involving: participation
nf (he ortho iotlo mil ml intent. in the cleavage of the
peroxide bond.3 Tho main product its a cyclic
lion of polymerization by the peroxide (I) is in efficient, probably bemuse of primary recombina tion of the radicals, hut leaving open (lie possibility of some cnnrutToiit, tionrudietil decomposition.
Kq. I
Eq.2
t'HiO
Eq. 3
GHjO-
OO II II o--c--o--c
NO,
compound (II), presumably arising from tho re combination of free radicals. However, tho initin-
(1) Tina Investigation was Riippnrtcil by n grant from the National Science Foundation.
The most likely nonradical reaction pill It would be decomposition into ion pairs (Equation 1?) nr 'ngmis
(2) J. E. Lclller, It. D. Faulkner, and C. C, Pctrcpoiiios J, Am. Chan, Hue,, 80, 5135 (tl)58).
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