1.ApplicationNumber: US-22173651-A
1.PublishNumber: US-2658913-A
2.Date Publish: 19531110
3.Inventor: HYMAN JULIUS
SILVERMAN MILTON

4.Inventor Harmonized: JULIUS HYMAN()
MILTON SILVERMAN()

5.Country: US
6.Claims:

7.Description:
(en)Patented Nov. 10, 1953 U I ED PATENT O E;
P FEN LENF Julius Hyman and Milton Silverman, Denver, 0610., ass'ignors', by mesne assignments, to Shell Developmen Com a y, yc vi Califa correla ion o Delaw r No Drawing. Application April 18, 1951,
' Serial No. 221,73?
1 Claims. (01. 260-543) This invention relates to new compounds {1 ful in the preparationoi naphthalene derivatives and to a process for' the production of naphthalene derivatives. More specifically, this invention relates to new compounds which essentially are derivatives of a highly chlorinated; partially hydrogenated 'tripheriylene, and to a process for the production of derivatives of naphthalene. therefrom in which the substituents arepreferentially in beta positionsand in'which all substituents or substituting groups are confined to a single ring of the naphthalene nucleus.
It has long been known to organic chemists that, in' general, multi substituted derivatives of naphthalene in which thesubstituents are confined to only one ring of the naphthalene nucleus generally could be obtained only with considerable difficulty and then only by means of procedures which require a multiplicity of operating steps. mono-substituted derivatives in which .the substituent is in the beta position and di-substituted derivatives in which .thelsubstituents are inthe 2 and 3 positions can be prepared only with great difiiculty andin poor yield. There are, of course, exceptions to the foregcing'general statements. Thus, by operating at relatively high temperature the sulfonation of .naphthalene .can be directed to give a mono-beta-sulfonic acid andby operating in appropriate solventsthe Friedel-Qrafts reaction Will, in some cases, yield a beta-substituted derivative. In general, however, substitution inithe naphthalene nucleus tends to occur primarily at an alphaposition. Also,,since,-th'e reagents, which are ordinarily used for direct substitution in aromatic compounds, introduce groups which tend to. inactivate abenzenoid ring system, further substitution in naphthalene, after the first, occurs inithe remaini g unsubsti tuted ring: asa result,..the polyesubstituted de rivatives obtained have substituents in bothof the rings. of the naphthalenenucleus. No simple processes have rhitl ert o been available which would restrict poly substitution to a single ring of the naphthalene system, and similarly no processes have 1 hitherto been available which wflld allow rec rena ei s'n. 9 .be d me- ,tiv es whenemployin h the halogens and i .w i ewh It has also been known that, in general,
lens and alpha-nitro-naphthalene are commonplace, the "corresponding betaderivatives are unavailable in commercial quantities and currently possess no economic importance since they can be obtained only via relatively complicated routes and almost necessarily, therefore, in poor yields. M V
"Among the objects of the present invention are to provide a novel process for the production of naphthalene derivatives to 'provide's'li'ch a 'proc ejs's forthe" production of a naphthalene derivative having a s'infgle'substituent' in the beta position; to provide such'a' process for'the production of a naphthalene derivative'havingtwo substituent'sjin the 2,3 positions; to provide such a process for the production of a poly-substituted naphthalene derivative in which all substituents are confined to asingle ring andto provide such processes which may ,be carried out comparatively ec'onomicallyand with comparatively high yields. It is amore specificobject of the present invention to prepare these naphthalene derivativesin' which thesubstituents are preferably in the beta position were which all substituents or substituting'groups are confined to a single ring 9f the aph h l nucleu b r in a e genated or' 'nitro substituted derivative of'a highl Chlorinated, partially hydrogenated triph'e'nylene, using 'a common substitution reagent. chlorine; brqrmne or' nitric me, then thermally decomposing this.
' Among further objects of this invention are to provide a new process for the production of novel derivatives of highly chlorinated, partially 1 hydrogenated triph'enylene in'which brominejchlor'ine, nitro rsulfonyI chloride is substitutedfin the b nz e a ri audio provide such {i nipounds which 'possjessjs n ui r utility for 'the "preparation" of j'naphthal'ene derivatives of the ""Additional objects and the novel features 01 this invention 111i tee e "apparent "from the description which v follows'f I efore describing theinovel processes and compounds of this" ir ivritionflfor a better understanding thereof, it'fis desirable to 'refeiftoa certain polychlo ated, partially ihydrogen'ated triphenylerie corn ound "pa'rticularly userui'in V I t, the roces or this invention and in the production 'oiftli fnovel compounds", reo'f.
rr in 0 Thus, the co-pending application of Julius Hyman and A. A. Danish, Serial No. 45,575, filed August 21, 1948, discloses and claims a novel Diels-Alder adduct which is obtained when hexachlorocyclopentadiene is caused to react with naphthalene; in that reaction, naphthalene reacts as a dienophile and adds two molar equivalents of hexachlorocyclopentadiene. The reaction involved may be represented by the following equation:
c1 01 H H 2 C1 c1 01 H H O1 As will be evident, the product of the foregoing equation, C20H8C112, is a polychlorinated, partially hydrogenated triphenylene, which for ease of reference is designated as CHTP, but may also be considered as containing highly chlorinated, polyhydro, di-endomethanophenanthrene fused to a benzene ring, since it is also evident from its structural formula that one ring, designated therein by means of the letter A, retains an intact benzenoid structure. It is further evident from its structural formula that a second ring, designated therein by means of the letter B, has attached thereto four hydrogen atoms which would be expected to be readily available for substitution.
It has also been found that the reaction which produced the compound CI-ITP is reversible, and at temperatures above about 150 C., it reverts to its generators, i. e. hexachlorocyclopentadiene and naphthalene. The actual reaction conditions which may be employed to prepare the compound CHTP are fully disclosed and discussed in the copending application above cited. However, in order to make reference to that document unnecessary, illustrative Example I which is given later shows how the compound CI-ITP has been prepared.
In accordance with the present invention, the
above compound CI-ITP is utilized in making the new compounds of this invention, and also in the novel process of making naphthalene derivatives which contain a single substituent in the 2 position, two substituents in the 2,3 positions, and all substituents, up to a maximum of four, confined to a single ring. For this purpose, substitutions may be made in the benzenoid ring A, as by chlorination, bromination, nitration, etc. As has been found, the halogenated polyhydro phenanthrene fused to the benzene ring appears to reduce the reactivity of that ring, and the ring A thus was not found to undergo the substitution reactions of a simple benzene ring. Nevertheless, it was also found that certain reaction conditions, equivalent to those necessary for substitution of a relatively highly deactivated benj of tetralin with bromine.
primarily saturated rings of tetralin can be conthe compound CHTP.)
4 zene ring, could be utilized to cause substitution,- as through chlorination, bromination, nitration, etc., in the ring A without affecting the ring B. The compounds produced by these benzene substitution reactions, when applied to CI-ITP, were completely new, since, except for the disclosure previously referred to the hereinbefore cited patent application, there is no record of the previous existence of a compound containing a benzene ring fused to a highly chlorinated, polyhydro, diendomethanophenanthrene.
Also, these compounds were quite different from the products which might be anticipated on the basis of the prior art. In general, compounds containing a benzene ring fused to an alicyclic ring system react with the reagents ordinarily used to introduce substituents into the benzene ring in such fashion as to bring about a change in the alicyclic ring rather than in the benzene ring. This can be illustrated by the reactions (The unsaturated and sidered to correspond to the rings A and B of When tetralin is treated with bromine, the alicyclic ring is brominated and by the subsequent loss of the elements of hydrogen bromide can ultimately be aromatized. In marked contrast, the di-endomethanophenanthrene nucleus in the compound CI-ITP was comp y inert and all reaction occurred in the benzenoid cycle A. Thus, the chlorination of the compound CHTP led finally to a tetrachloro derivative in which the chlorines were attached to the carbon atoms numbered 1, 2, 3, and 4 in the structure CHTP given above. Similarly, bromination gave a dibromo compound in which the two bromine atoms were attached to the carbon atoms numbered 2 and 3, while nitration gave a mono-nitro derivative in which the nitro group was attached to the carbon atom numbered 2.
Unexpectedly, also, it has been found that these new derivatives of CI-ITP possess highly important utility for the preparation of unusual but valuable substituted naphthalenes. Thus, in further accordance with this invention, the above derivative of CHTP may merely be heated to produce a desired substituted naphthalene. Investigations have shown that the formation of derivatives of CI-ITP, of the type already referred to, does not appreciably affect the ease with which hexachlorocyclopentadiene can be split from the compounds thus formed. Heating the new derivatives of CHTP to about the same temperatures required to cause CI-ITP itself to revert to its generators caused these derivatives to form hexachlorocyclopentadiene and corresponding derivatives of naphthalene. As a result, it follows that substituted naphthalenes, in which all of the substituents are contained in one ring, and also substituted naphthalenes in which the substituents are in the beta position only, can now readil be prepared. Thus, for example, when the nitro CI-ITP hereinbefore alluded to was heated, beta-nitronaphthalene was obtained in high yield.
The conversion of derivatives of CHTP to a substituted naphthalene and hexachlorocyclopentadiene was readily accomplished by heating the CHI? derivative to a temperature within the range of C.- 300 C. This conversion process step was not critical as to operative conditions since several variations have worked satisfactorily, It was carried out with the CHTP derivative dissolved or suspended in a relatively inert solvent andi it has-been carried-. out; without the use, era. solventby. efiectingi destructive. distilla,. tion of the CHTP derivative in order-toobtain the desired substitutednaphthalene and regenerate hexachlorocyclopentadiene in relatively pure form. At the lower temperatures indicated, it may be necessary to.prolong the heating period so that the: compound is at the indicated tem-.
perature for as. long'as 24.hours; atthe. higher temperature indicated; the conversion has been; completed an hour. or less.. Even. higher tem-..
peratures have been; employed when conditions weresq esulateq. astosho'rt n timefor which the organic substances were subjected to high temperatures. In the illustrative examples which fo'llowlaten conditionswhich.havebeen-employed for the. decomposition of: CHTP: derivatives: into hexachlorocyclopentadiene.andtsubstituted naphe thaleneswill be concretely'setforth. It must, of course, be remembered that these examples are illustrativeronly; once .the general procedures: required: forthisdecomposition are disclosed; those skilled in the art will readily see how.many-modi-. eiian canhe n mdmm ami all. t h se-modifications thus necessarilyi all withinthe scope of thepresent invention,
It is evident; that; the novel and unexpected discoveries hereinabove disclosed. provide a basic and whollynew process for the preparation of naphthalene derivatives,- of a type hitherto difiicultto prepare and; available only uneconomically; Inorder to prepare such napthalene derivatives; it is now only-requiredthat naphthalene be reacted with hexachlorocyclopentadiene-- in order to form CHI'P; that the CHTP thus prepared: be transformed, by a substitution reaction to an appropriate derivative, andthat the CHI? derivative thus; obtained be thermallydecom posed at relatively low temperatures in order to produce the desired naphthalene derivative and recover the relatively pure hexachlorocyclopentadiene. Since all-of-these individualstepsof this proce sp pceeded e d ly-a d in od-y d, d since the recoyery -of'-hexachlorocyclopentadiene wasnearly quantitative; it is apparent-thatnaphthalene derivatives made by this-process can, incomparison with procedureswhich previously were required; be obtained relativelyinexpensively.
As tvillindeed be obvious-to those-skilled in-theartof the synthesis of aromatic compounds, the
procedures which may-be employed are numerous and varied; these various proceduresdonot; in themselves. constitute critical iactorsior theinventionhere disclosed. While the fact that the compound GHTP formed benzenoid: derivatives;
under conditions sometimes employedfor-benzene or benzenoid substitutions; and whilethe comu s-thus= ai iedarenew ndn s essun xpected properties, the conditions which. can; be employed for producing these-derivatives correspond to those well known'to the art. Thus, once one .skilled-injhe-art; is mad.e..=.aware-;o f -thefact;
that; these; derivatives have been prepared; in the:
fashion already; indicated; and is, further in, formed: that the;..ben cnoid= nucl s..in1 heompound: CHTP wasofoun rin: eff ct. p e; a-
tivelsn. non-reactive.-nucleus. and-z houlitherefpre, treated: under; subs antially? evere; reaction; .na csiresiz erivativesi.
the information whichisrequired in orderto prepare i iifififii Qti lfi? f s c l e made known to him. .Mangoj the examples which follow will" illustrate procedures which havebeen employed iorithepreparatiomot-derivativesiof'the compound. Itamustlhoweveit. be emphasized that, these. examples are: illustrate tive only: and that a variety of othenprocedures; normally. employed; forpreparing. deriyativeexot aromatic compounds, can-likewise be: employed? to preparedderivativesiofrthezcompoundzGHIIB. All such procedures areproperly within; the. scope: otj. the invention here, disclosed.
A:- P pa a on. of CHTP:
Into a three liter flask wereplaced 378e0 g'. of naphthalene and 162 241; g;. of; hexachlorocycloa pentadiene having a 94.2%v purity.- (=mole.r.a.ti0; 1:2). The resulting solutionwas. heated. at 157?. C.- for hours; at, the end of'that'time, the reaction mixture was-chilled; whereupon a large quantity of crystalline material" separated: from th solution. These. crystals wereseparatedgonar filter, washed, with. acetone and dried There.- were thus obtained536-1 g: of'asubstancaconfi eluded; to be. .meltingat; 2;l1 .5 1- -213;5% Analysis (by infra-red spectroscopy)j indicated"; that the solution; remaining after separation of: the precipitatedcrystals -Sti110llt2til18dilfi4 grams. of'CHTP.
B. Preparation of TetrachlormG'HTP- A mixture containing; grams-.of CHQI'R. .225; ml. of tetrachloroethane and: 0.5 gramoof iron powder washeated to 95 Gmat which tempera.- ture all of the CHI? dissolved. in: the Sava t. Chlorine was passed, throughthe mixturaiona; 5 hour period, whileit was maintained.at a;atemperatureof 90-105 0. Nearthe end..0f;chlorinar.-. tion, a considerable, amount, of solid; separated. from the mixture. The. reaction mixturewas then cooled and filtered; the.crude;product.thusl obtained was dissolved in hot toluene and treated: with adecolorizing charcoal; and the.clarifi edl solution was diluted with about one-half, its; volume of methanol. A.solid;product crystallized from the resulting solution,:. it was.- separated,"v washed with methanol anddried, and was found-, to melt at 226-227 C. Elemental analysis showed the solid to be tetrachloro-CHTP. The yield of this material (150 grams) was in excess of 84% of the quantity theoretically obtainable.
C. Preparation. of 1,2,3,4?tetraehloronaphthalene; fromietrachloro-CHTP Preparation-of 2,3 dz'bromo CHTP One hundred grams of CI-ITP, 200 ml. oftetrae. chloroethane and 0.5 gram ironpowder (reduced. by hydrogen) were placed'in a flask fitted with a reflux condenser and a dropping funnel... Thee mixture was heated to reflux (bywhichtimethe;
CI-ITP had dissolved in the tetrachloroethane) and 30 ml. of bromine(twice--theory, to'- com: pensateior bromine lost by HBr entrainment and" by brominationof the solvent or itsimpuritiesir dissolved in 30 ml: oftetrachloroethane;'; was
added: dropwise: over aperiod of anhour: Re-
fluxing was continued for an additional two hours; The bromine and FeBra which formed were removed by shaking the warm solution with aqueous sodium bisulfite and subsequently washing it with water. The solution was then dried and treated with a decolorizing charcoal. The warm solution, obtained after filtration, was then diluted with about 400 ml. of methanol. A crystalline solid separated which melted between 220-222 CL, and the yield was approximately 100 grams. It was concluded to be dibromo CHTP after analysis including the following:
Calculated for C20H6C112B122 C, 28.8; H, 0.72 Found: C, 28.5; H, 0.75
Preparation of 2,3-dibromonaphthalene from dibromo C'HTP Dibromo CHTP (220 grams) was introduced into a 200 ml. flask by melting it as it was introduced. When all the material was molten, the flask was mounted -with a Claisen head, a condenser and a receiver and the distillation system was carefully evacuated to an absolute pressure of 70-100 mm. Hg. The flask contents were heated and at a pot temperature of 220 C., hexachlorocyclopentadiene distilled over. Distillation was continued until the production of hexachlorocyclopentadiene became very slow and small amounts of solid appeared in the material distilling over. The dark residue left in the flask, while still hot and fluid, was poured into benzene and heated with decolorizing charcoal. The solution remaining after the removal of the charcoal was diluted with methanol: a crude brown crystalline solid was deposited by this solution. This crude solid was recrystallized from heptane; there was thus obtained a light brown product which crystallized in flakes and melted between 137-139 C. By treatment with cuprous cyanide in pyridine solution this solid was converted to the known 2,3-dicyanonaphthalene. This fact, together with its melting point and its elementary analysis, unambiguously identified the solid obtained as 2,3-dibromonaphthalene.
EXAMPLE III Nitration of CH TP, mode 1 Into a three liter flask fitted with an eflicient stirrer, was placed 1120 grams of concentrated sulfuric acid, 880 grams of concentrated nitric acid and 400 grams of CHTP (mole ratio,
H2504: HNOs CHTP=17.5 16.5 1)
The suspension was vigorously stirred and maintained, for a period of approximately 5 hours, at a temperature of approximately 100 C. During the course of this time, the suspension of essentially white solid originally present gave way to a suspension of a light yellow solid. At the end of five hours, the mixture was cooled, and brought on a filter. The light yellow solid crystalline material thus separated was washed with water and dried; it melted between 203-207 C. A mixture of this solid with an equal weight of the starting material CHTP melted below 200 C., while the solid analyzed as follows:
Calculated for C2QH7CI12NO2 Cl, 59.2; N, 2.0 Found: Cl, 59.0, 59.5; N, 2.0
The solid was thus concluded to be a mononitro CI-ITP. Repeated recrystallization from hexane of the solid melting between 203-207 0., caused its melting point to rise to 222-223" C.
, As the nitration above described proceeded, the
course of the reaction was followed by infra-red spectroscopic analysis, and the following results were obtained:
' 0 Percent Percent Mono 7 Hours at 100 O. OHTI, NOTCHTP Nitratio'n of C'HTP, mode 2 The procedure employed, except for the mole ratios used and the duration of the nitration reaction, was identical with that of mode 1 of this Example III. The reactants were used in the molar ratio of H2SO4:HNO3:CHTP=33.8:23.5:1.0, while the nitration was continued for 8 hours. A yield (based on CHTP used) of of theoretical was obtained.
Preparation of beta-nitronaphthalene from mono-nitro C'HTP (mode 1) Theory Found Percent beta-nitronaphthalcnc Percent hexachlorocyclopentadiene This distillate was carefully fractionated in vacuo (1.0 mm. Hg abs.) to separate the hexachlorocyclopentadiene from the naphthalene derivative; the 0501s was collected at 19-84" C. The residue in the distilling flask crystallized on cooling, and was taken up in ethanol and treated with decolorizing charcoal. After separation of the charcoal on a filter, the ethanol solution was diluted with water and slowly cooled, and yellow crystals of nitro-naphthalene separated. One additional recrystallization from aqueous ethanol gave a product melting at '78-79 C. An authentic sample of beta-nitronaphthalene, obtained by classical but complicated methods, also melted at 78-79 C. An equal weight mixture of these two materials also melted at 78-'79 C. The product obtained by the method just described gave the following analysis:
Calculated for nitronaphthalene, CmH'zNO: C,
69.4; H, 4.2. Found: C, 69.2; H, 4.1.
The product obtained by the foregoing method was also reduced to the corresponding amine and the acetyl and benzoyl derivatives of the amine were prepared. The amine thus obtained, and its two derivatives, were compared with an authentic sample of beta-naphthylamine and its corresponding derivatives and found to be identical. The product was thus unambiguously identified as beta-nitronaphthalene.
Preparation of beta-nitronaphthalene from mono-nitro CHTP (mode 2) A solution containing 200 grams of mono -nitro .9- dissolved in 500 grams: of xylene was pumped, at the rate-'of 48 ml. per minute, through a: /2 'I'JD. nickel tube-heated over an eight inch length=ta temperature of 329.5-371' C. The efiluent vapors from the cracking tube were condensed -and'stripped of the solvent xylene. Analysis byinfra-red spectroscopy'of theliquid residue remaining after the xylene had been removed indicated that itcontained 23.0% of betanitronaphthalene (theory, 24.1% The betanitronaphthalene was isolatedby the method; described in Example VIII.
EXAMPLE 1V Preparation of CHTP-sulfonyl chloride: (FriedeZ-Crafts reaction) A mixture of 27.0 grams (0.0.4'mole) of CHTP, 75- cc. of 802012 and 6.2 grams (0.046 mole) of AlCls were refluxed for 4 hours. The reaction mixtureturned a dark purple and H01 gas was evolved. The reaction mixture was then poured into 200-300 cc. of ice Water; the mixture was extracted with ethyl acetate; and the ethyl acetate waswashed with water, separated and dried over anhydrous sodium sulfate. After removal of the dryingagentuon a. filter, the ethyl acetate solventwasstripped fromthe product by distillation, and the heavy oil which remained was dissolved in 100 ml. of warm hexane. When the hexane solution thus obtainedwas cooled, a solid separated. The solid was isolated on a filter and washed with hexane; the crude solid melted between 243 -253" C. Recrystallization of this crude solid from nitromethane raised its melting point to.- 2527-25? C., and it: was concluded to be the expected CHTP sulfonyl chloride afterj the-following analysis:
Calculated for C2oI-I'1C113O2SZ CI, 59.7; S, 4.1. Found: Cl, 60.0; S, 4.6.
As has already been indicated, there are many variations which can be employed to produce CHTP derivatives other than the procedures hereinbefore specifically set forth. Thus, the nitro derivative of Example III, mode 1, can be reduced either chemically, using such reagents as zinc and sulfuric acid in the presence of acetic acid, to produce an amine; or, under suitably modified conditions, to produce the acetyl derivative of an amine; or it can be reduced catalytical- 1y to produce the amine itself. Similarly, it can be partially reduced to produce azo-derivatives, hydrazo-derivatives and hydroxyl amine derivatives.
A will be evident, the process herein disclosed can be employed to produce a variety of naphthalene derivatives. Thus, for example, the compound CI-ITP can be methylated to produce a methyl derivative. This methyl derivative can be oxidized to the corresponding carboxylic acid and the carboxylic acid thus obtained can be gently pyrolyzed to produce beta-naphthoic acid. While beta-naphthoic acid is known, it cannot be obtained readily by the methods hitherto employed. However, application of the process just outlined can make beta-naphthoic acid easily and relatively cheaply available.
It should be emphasized that the process herein outlined is a fundamentally new process for the preparation of naphthalene derivatives of a type previously extremely difficult to prepare and generally commercially unavailable. This fundamentally new process comprehends many modiflcations of the steps which may be employed for producing the necessary intermediates through 10 which-it proceeds; accordingly, all such modifications of the individual process-steps-areprpperly included within its scope. This invention, therefore; is not tobelimited by the examples crane-illustrative; material hereinbefore set forth but only by thefollowing claims.
What is claimed-is 1. A process for the production of anaphthalene derivative which comprises reacting the adduct of naphthalene; and hexachlorocyclopentadiene, in which two molecules of hexachlorocyclopentadiene are fused with a single ring of naphthalene witha reagent which introduces a substituent from the group consisting of nitro, bromine and chlorine into a benzenoid ring, and then heating said substituted adduct to a minimum temperature of C. to produce hexachlorocyclopentadiene and a substituted naphthalene in which all substitutents up to a maximum of four are confined to the single ringand there is a substituentin the beta position.
2; A process for the production of hexachloro cy-clopentadiene and a substituted naphthalene in whichall substituents are confined to a single ring and there is a substituent in thebetaposition, as. defined in. claim 1, wherein said substitut'ed' adduct isheated to a temperature of substantia1ly1'50-300 C.
3..A process of the production of hexachlorocyclopentadiene and a substituted naphthalene in which all substituents are confined to a ingle ring and there is asubstituent in the beta position, as, defined in claim 1, wherein said substie tutedadduct is heatedat not above atmospheric pr ssure- 4. A process for. the production of. betarnitror naphthalene and -'hexachlorocyclopentadiene which comprises reacting the adduct of naphthalene and hexachlorocyclopentadiene, in which two molecules of hexachlorocyclopentadiene are fused With a single ring of naphthalene, with nitric acid to introduce a N02 group into the unreacted benzenoid ring, and then heating said mono-nitro adduct to a minimum temperature of 150 C. to produce hexachlorocyclopentadiene and beta-nitronaphthalene.
5. A process for the production of 2,3-di'bromonaphthalene and helachlorocyclopentadiene which comprises reacting the adduct of naphthalene and hexachlorocyclopentadiene, in which two molecules of hexachlorocyclopentadiene are fused with a single ring of naphthalene, with bromine to introduce bromine atoms into the unreacted benzenoid ring, and then heating said di-bromo adduct to a minimum temperature of 150 C. to produce hexachlorocyclopentadiene and 2,3-dibromonaphthalene.
6. A process for the production of a highly chlorinated, partially hydrogenated triphenylene derivative, which comprises the step of reacting the adduct of naphthalene and hexachlorocyclopentadiene, in which two molecules of hexachlorocyclopentadiene are fused with a single ring of naphthalene, with a reagent which introduces a substituent into the beta position of the unreacted benzenoid ring, said substituent being from the group consisting of Cl, Br, N02 and SOzCl.
7. A process for the production of a highly chlorinated, partially hydrogenated triphenylene derivative, which comprises the step of reacting the adduct of naphthalene and hexachlorocyclopentadiene, in which two molecules of hexachlorocyclopentadiene are fused with a single ring of naphthalene, with nitric acid which in- 11 troduces a N02 group into the beta position of the unreacted benzenoid ring.
8. A process for the production of a highly chlorinated, partially hydrogenated triphenylene derivative, which comprises the step of reacting the adduct of naphthalene and hexachlorocyclopentadiene, in which two molecules of hexachlorocyclopentadiene are fused with a single ring of naphthalene, with bromine which introduces two bromine atoms into the 2,3-positions of the unreacted benzenoid ring.
9. A process for the production of a highly chlorinated, partially hydrogenated triphenylene derivative, which comprises the step of reacting the adduct of naphthalene and hexachlorocyclopentadiene, in which two molecules of hexachlorocyclopentadiene are fused with a single ring of naphthalene, with chlorine which introduces four chlorine atoms into the 1,2,3A-positions of the unreacted benzenoid ring.
10. A process for the production of a highly chlorinated, partially hydrogenated triphenylene derivative, which comprises the step of reacting the adduct of naphthalene and hexachlorocyclo pentadiene, in which two molecules of hexachlorocyclopentadiene are fused with a single ring of naphthalene, with sulfuryl chloride which introduces a $0201 group into the beta position of the unreacted benzenoid ring.
11. The substituted derivative of the adduct of one mole of naphthalene and two moles of hexachlorocyclopentadiene in which the substituent is from the group consisting of nitro, sulfonyl chloride, bromine and chlorine, the nitro and sulfonyl chloride each being in the 2 position, the bromine being in the 2,3 positions and the chlorine being in the 1,2,3A positions.
12. A process for the production of 1,2,13,4- tetrachloronaphthalene and hexachlorocyclopentadiene which comprises reacting the adduct of naphthalene and hexachlorocyclopentadiene, in which two moles of hexachlorocyclopentadiene are fused with a single ring of naphthalene, with chlorine to introduce chlorine atoms into the unreacted benzenoid ring, and then heating said tetra-dichloro adduct to a minimum temperature of C. to produce hexachlorocyclopentadiene and 12,3,4-tetrachloronaphthalene.
13. The mono-nitro substituted derivative of the adduct of one mole of naphthalene and two moles of hexachlorocyclopentadiene in which the N02 group is in the 2 position.
14. The substituted 2,3-di-bromo derivative of the adduct of one mole of naphthalene and two moles of hexachlorocyclopentadiene.
15. The substituted 1,2,3A-tetra-chloro derivative of the adduct of one mole of naphthalene and two moles of hexachlorocyclcpentadiene.
16. The mono-sulfonyl chloride substituted derivative of the adduct of one mole of naphthalene and two moles of hexachlorocyclopentadiene in which S0201 group is in the 2 position.
JULIUS HYMAN. MILTON SILVERMAN.
References Cited in the file of this patent FOREIGN PATENTS Number Country Date 234,912 Germany May 26, 1911 OTHER REFERENCES Huntress, Organic Chlorine Compounds,
pages 216-? (1948).