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OSWALD AND NOEL
Periodate ozidation. For oxidation, 100 mg. of sugar was dissolved in 50 ml. of water, 50 ml. of 0.3M solution of sodium periodate added, and the mixture kept a t 25" in the dark. Formic acid was liberated with 0.05N sodium hydroxide solution added in 5ml. aliquots. Maximum amounts were formed in 3 days. To test for formaldehyde, 10 mi. of the final oxidation mixture was distilled at 60' under reduced pressure to collect 7 ml. of distillate in a receiver at 0". One milliliter of fuchsin sulfurous acid was added and after 10 min. 1 ml. of concd. hydrochloric acid was added. While n-glucose gave a positive blue color, both anhydrides gave a negative test. Periodate oxidation also produced as one end product an ether which could be characterized. To accomplish this, anhydrides I and I1 were separately oxidized in 685mg. quantities with 5.1 g. of sodium meta-periodate in 50 ml. of water. After 5 hr. a t 25O, 5 ml. of 2N sodium hydroxide solution was added, followed by an excess of sodium borohydride. Reduction was allowed to occur at 25" for 2 hr. and at 45" for 2 hr. The solution was made acid with 2N sulfuric acid and neutraliied with sodium hydroxide solution. Water was removed by distillation under reduced pressure and the dry residue was extracted several times with absolute tetrahydrofuran. The combined extracts were dried over anhydrous sodium sulfate and concentrated to 10 ml. To this was added 1.4g. of 2,4dinitrobenzoyl chloride and 1ml. of dry pyridine and the mixture was heated 30 min. at 70". After filtration and distillation to dryness under reduced pressure, the residue wm dissolved in warm benzene. This solution was washed first with 2 N sodium hydroxide solution and then with water and was dried over anhydrous sodium sulfate. The diester crystallized on addition of ether. After recrystalliaation from a mixture of five parts of heptane and one part of dioxane
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the melting point was 154O, undepressed on admixture with the authentic sample prepared below. The compounds were also identical in infrared and x-ray patterns. The authentic sample of &@'-dihydroxyethyl ether di2,4dinitrobenzoate was prepared from a commercial sample of &@'-dihydroxyethyl ether as described above. Rant mol. wt., 510; calcd., 494. Anal. Calcd. for C I I H ~ ~ N ~C,O43.73; ~: H, 2.85;N,11.33. Found: C, 43.82;H, 2.94;N,11.03. Hydrolysis of anhydrides I and II. Approximately 5 mg. of anhydride waa mixed with 1 ml. of 48% hydrobromic acid and the solutions were heated in a sealed tube for 15 min. at looo.The contents were diluted with 10 ml. of water and 2 ml. of ethanol. An excese of silver carbonate was added, the mixture filtered and the filtrate treated with hydrogen sulfide. After admixture with carbon, the solution was filtered and concentrated under reduced pressure to a sirup which waa taken up in 1 ml. of water. This solution was analyzed by paper chromatography using Whatman No. 1 paper, ethyl acetatepyridine-water (10:4:3 v/v) as the irrigant and silver nitrate solution as the spray reagent. Anhydride I gave only one hydrolysis component, which had a flow rate equivalent to that of D-glucose. Anhydride I1 gave evidence of two components in what by visual comparison appeared to be equal amounts, one with the flow rate of D-glucose and one with the flow rate of Dgalactose.
Acknowledgment. The authors thank the National Science Foundation for a grant for partial support of this work. LAFAYETTE, IND.
[CONTRIBUTION FROM THE RESEARCH DEPARTMENT, INPERIAL OIL LIMITED]
Organic Sulfur Compounds. IV.'* Some Addition and Co-oxidation Reactions of 4-Chlorobenzenethiol with Dicyclopentadiene and Aldrin ALEXIS A. OSWALDlb AND FERNAND NOEL Received May 31, 1980 4-Chlorobenzenethiol readily adds to exo- and endo-dicyclopentadienes and Aldrin (VIII) by a radical mechanism to yield the ex0 and endo isomers of Pohlorophenylmercaptodihydrodicyclopentadiene(IV and V) and 2-p-chlorophenylmercaptoendo-5,6,7,8,9,9-hexachloro-exo-endo-1,2,3,4,4a,5,8,8a-octahydro-1,4,5,~dimethanonaphthalene (IX). When 4chlorobenzenethiol solutions were air oxidized with any of the above diolefins, unstable hydroperoxide intermediates (XIII, XVI, XVIII) were obtained. The hydroperoxide intermediate of the thiol-Aldrin co-oxidation, 2-p-chlorophenylmercapto-3hydroperoxy-endo-5,6,7,8,9,9-hexachloro-e~~e~~~l,2,3,4,4a,5,8,~octahy~o-l,4,5,~~methanonaphthalene (XVIII) waa isolated as a colorless, crystalline substance. In solution, i t rearranged to the corresponding 2-gchlorophenylsulfinyl-3hydroxy derivative (XIX). It is suggested that similar co-oxidation and not addition reactions of thiols and dicyclopentadiene arc responsible for gum formation in some cracked gasolines.
The results of investigations of radical type mercaptan-olefin addition and co-oxidation reactionsIag2 suggested that similar reactions of diolefins and mercaptans may occur. The examination of diolefin-mercaptan addition and co-oxidation
was of interest from the viewpoint of gum formation in cracked gasolines. Early studies, summarized by Elliss and Gruse4 concluded that diolefins cause (3) C. Ellis, The Chemistry of Petroleum Derivatives, The Chemical Catalogue Co., Inc., N. Y., (1934) Vol. I, pp.
(l)(a) A. A. Oswald, J. 076. Chem. 26, 842 (1961). (b) Present address: Central Basic Research Laboratory, Esso Research and Engineering Co., Linden, N. J. (2) A. A. Oswald, J. Org. Chem.,24,443 (1959).
893-903. (4) W. A. Gruse, "Gum in Gasoline," Section in Vol. 11, p. 1016 of The Science of Petroleum, Oxford University Press, London-New York (1938).
OCTOBER 1961
BRaANlc SULSUR COMPOUNbS. IV.
3949
In this laboratory, it was found that an equirapid gum formation in gasolines because they peroxidize and polymerize readily. Schultze6 found molar amount of 4-chlorobenzenethiol readily that the addition of dicyclopentadiene to a “motor adds to endo-dicyclopentadiene (I) in a nitrogen spirit” increased gum formation. Kruber and atmosphere to yield a light yellow liquid sulfide Schade6 suggested that the deleterious effect of (IV), which can be distilled in vacuo without demercaptans on “motor benzene” stability was composition. The addition is exothermic even in due to their addition to cyclopentadiene and di- the absence of any catalyst. The same addition cyclopentadiene. The latter compounds are com- products can be obtained by catalysis with a mon components in very severely cracked naphtha.? peroxide (e.g. t-butyl hydroperoxide) or ultraviolet Our studies of mercaptan-dicyclopentadiene addi- light (Table I). Therefore, it is proposed that the tion and oxidation of the addition product sug- addition proceeds by a radical mechanism. Two moles of 4-chlorobenzenethiol could not gested that the formation of relatively stable sulfides by the mercaptan diolefin addition does be added to one mole of dicyclopentadiene in the not explain why mercaptans are such effective absence of catalyst. The second mole of thiol promoters of gum formation. Therefore, the remained unchanged. This showed that normally co-oxidation of diolefins and mercaptans was also only one double bond of the dicyclopentadiene studied to obtain a better explanation for these takes part in the addition reaction. Differences between the reactivities of the two double bonds and related phenomena. In the first part of our studies, endo-dicyclopenta- in the dicyclopentadiene molecule were reported in diene (I), which is formed by the spontaneous the literature. The double bond of the bicyclodimerization of cyclopentadiene at room tempera- heptene system was found to be more active in the ture,8 was chosen as a diolefin with isolated double addition of phenylazide,” nitrosyl ~ h l o r i d e , ~ ~ ~ ~ ~ .~~tl~ water,18 and various bonds. A reactive aromatic mercaptan, 4-chloro- h y d r ~ g e n , ~ ~bromine,lB*1’ alcohols and phenolsg to dicyclobenzenethiol, was selected for the experiments acids,11+1u-21 because aliphatic mercaptans were too sluggish pentadiene. to react with dicyclopentadiene in the absence of The addition of phenylazide to dicyclopentadiene catalysts. The reactivity of 4-chlorobenzenethiol and derivatives was examined by Alder and is comparable to the toluenethiols normally found and was found to take place very readily in cracked petroleum distillates. with compounds containing the bicyclo [2.2.1]A. Addition reactions. 1. Dicyclopentadime-4- heptene group. The lack of phenylazide addition to chlorobenzenethiol. The possibility of addition of dihydrodicyclopentadiene, for example, was used thiols to endo-dicyclopentadiene was first mentioned to prove the absence of the bicycloheptene group. by Kruber and Schade in 1933.6 They recovered a In a similar manner in our work, the absence of high boiling oil of 14.8% sulfur content, presum- reaction between the 4-chlorobenzenethiol-dicycloably ethylmercaptodihydrodicyclopentadienefrom pentadierie addition product and phenylazide a mixture of ethanethiol and dicyclopentadiene indicated that the addition reaction took place after standing for fourteen days. Bruson and Riener at the double bond of the bicycloheptene part of in 194j9reported that the addition of mercaptoace- dicyclopentadiene. tic acid to dicyclopentadiene gave carboxymethylAnother problem, associated with the structure mercaptodihydrodicyclopentadiene. However, the of the addition product, is the possibility of stereoabove authors did not examine the mechanism of isomerization to the so-called endo and ex0 forms. the addition. The endo-dicyclopentadiene is formed exclusively Cristol and BrindelllO found that p-toluenethiol when cyclopentadiene is dimerized. On heating readily adds to norbornene (bicyclo [2.2.1 ]-hept2-ene) by a radical mechanism. When equimolar amounts of norbornene and cyclohexene were (11) K. Alder and G . Stein, Ann., 485, 223 (1931). allowed to compete for p-tolumethiol the (12) Kramer and Spilker, Ber., 29, 588 (1896). product distribution indicated that norbornene (13) H. Wieland Ann., 446, 20 (1925). is about forty-five times as reactive towards the (14) H. Staudinger, Helv. Chim. Acta, 7, 27 (1024). p-tolyl mercapto radical as is cyclohexene. (15) H. Wieland, Ann., 446,25 (1926). (16) H. Staudinger and A. Rheiner, Helv. Chim. A d a , 7, 8,23 (1924). (5) G . R. Schultae, Oel-Kohle-Erdoel-Teer, 14, 113 (1938). (17) H. Staudinger and H. A. Bruson, Ann., 447, 97 (6) 0. Kruber and W. Schade, Brenmtof-Chem., 14, 124 (1926). (1933). (18) H. A. Bruson and T. W. Riener. J . A m . Chem. SOC.. (7) S. F. Birch and W. D. Scott, Ind. Eng. Chem., 24, 49 67,723 (1945). (1932). (19) P. D. Bartlett and A. Schneider, J . A m . Chem. SOC., (8) A. Etart and P. Lambert, C m p t . rend., 112, 945 68,6 (1946). (1891). (20) H. A. Bruson and T. W. Riener, J . Am. Chem. SOC., (9).H. A. Bruson and T. W. Riener, J. A m . Chem. SOC., 67,1178 (1945). 6 8 , s (1946). (21) F . Bergmann and H. Japhe, J . Am. Chem. Soc., 69, (IO) S. J. Cristol and G. D. Brindell, J. A m . Chem. Soc., 1826 (1947). 76,5699 (1954). (22) I
