PRIEDEL AND CRBFTS’ REACTION. PART I. 1335 CXLIII.-Mochjkation and Extension of the Friedel and Crafts’ Reaction. Part I. By JNANENDRA NATH RAY. RADZIEWANOVJSKI (Ber. 1895 28 1139) suggested some modifi-cations of the Friedel-Crafts’ reaction in one of which he used a mixture of aluminium powder and mercuric chloride. He pre-pared ethylbenzene in small yield but did not obtain any tri-phenylmethane in the condensation of chloroform and benzene. Von Gulewitsch (Rer. 1904 37 1560) studied the interaction of mercuric chloride and aluminium in benzene and isolated a com-pound C,H6,A1C1,,RgC1. A similar compound was formed with toluene. It was thought that i f this double compound were employed as a catalyst t,he secondary changes that rendered Radziewanowski’s reaction unsuccessful might disappear.This expectation has been amply realised. Von Gulewitsch showed t8he course of the reaction to be C6H6 + A1 + 2HgC1 -+ C6H6,A1C1,,HgC1 + Hg. The mercury liberated as above forms an amalgam with the unchanged aluminium but when an excess of mercuric chloride is employed this tendency to amalgamate is reduced inasmuch a 1336 RAY MODIFICATION AND EXTENSION OF THE the whole of the aluminium is utilised in reducing mercuric to mercurous chloride. The success of the reaction depends on the non-formation of the amalgam as otherwise it acts concurrently with the double compound. Some interesting products have been isolated in the condensation of the hydrocarbons with chloroform carbon tetrachloride benzyl-idene chloride etc. Thianthren has been prepared in an 80 per cent.yield from benzene and sulphur. This compound was obtained in small amount along with phenyl niercaptan phenyl sulphide and phenyl disulphide by Friedel and Crafts ( A n n . Chim. Pliys. 1888 [vi] 14 438) in the condensation of benzene and sulphur wit9h aluminium chloride whilst Genvresse ( 7 3 u I I . SOC. chim. 1897 [iii] 17 599) observed the formation of thianthren and isothianthren in the same reaction. 9 10-Diphenyl-9 10-dihydrosnthracene is formed by the con-densation of benzene and chloroform whilst in the ordinary Friedel-Crafts' reaction (Annalen 1878 194 254 ; 1885 227, 107) triphenylmethane cliloroarylmethanes and t'etraphenyl-ethane (h'er. 1893 26 1952) are the products. The same compound is obtained by the interaction of benzylidene chloride and benzene.Carbon tetrachloride and benzene give 9 9 10 10-tetmphenyl-9 1 0-dihytZroanthrace~ze which is also obtained from benzotri-chloride and benzene whilst in the usual reaction triphenyl-methane chloroarylinethanes ( A nnnlen 1878 194 254) and tetra-phenylethylene (Ber. 1893 26 1952) are obtained. Similarly dimethyl-9 10-ditol~l-9 10-tlilaydroan thracene has been obtained from chloroform and toluene. In this condensation, using aluminium chloride Schwarz ( R e r . 1881 14 1530) pre-pared tet~atolylet~hane which has ilhe same melting point ( 2 1 5 O ) and empirical formilla hiit a niixture of the two melts at, 20G-208°. Renzylidene chloride and toluene yield dimethy!-9 10-diphcnyl-9 3 O-diJiyilron,ntJ~raceiie.Finally chloropicrin and benzene under the action of the reagent, furnish w-nitrotriphenylmethane previously obtained by the direct addition of nitrogen peroxide to triphenylmethyl (Schlenk Mair and Bornhardt BPT. 1911 44 1172). Boedtker (BUZZ. Sot. chim. 1908 [iv] 3 726) states however that all aliphatic nitro-compounds lose their nitro-groups under the influence of aluminium chloride arid obtained triphenylmethane and some triphenylcarbinol in this reaction FRIEDEL AND CRAFTS' REACTION. PART I. 1337 E x P E R I M E N TAL. To a mixture of 20 C.C. of dry benzene and 20 grams of mercuric chloride contained in a flask with reflux condenser 1 gram of aluminium powder was added gradually and the flask vigorously shaken. The heat of the reaction caused the benzene to boil and the flask was occasionally cooled in an ice-bfth.A green crystal-line mass eventually separated and the reaction was completed by immersing the flask in tepid water for half an hour. The mercury liberated in the reaction was reiiioved and the preparation of the catalyst was coi~plete. In all the reactions described below the components were well agitated by a mechanical stirrer. Acetophenone.-The calculated amount (I niol.) of acetyl chloride was added through the condenser in small quantities a t a time the mixture allowed to reiilain for two hours a t the ordinary temperature and then heated t,o 400 for an hour. On cooling i t was decomposed with water and the oil extracted with benzene, the benzene solution being dried and finally fractionated.The yield of acetophenone was GO per cent. of the theoretical whilst by Friedel and Crafts' method i t is 55.5 per cent. p-Tolyl iMethyl Ice tone.-Following an almost identical method, from 33 C.C. of toluene 2.5 grams of aluminium and 45 grams of mercuric chloride 16.1 grams of this ketone were obtained. 9 Thianthren C,H4<s>C,H,.-The cat'alyst was prepared from 2.5 grams of aluminium 45 grams of mercuric chloride and 30 C.C. of benzene; I0 grams of flowers of sulphur were added and the mixture was heated on the water-bath until hydrogen sulphide was no longer evolved. The product on cooling was decomposed with ice filtered and the residue repeatedly extracted with chloro-form from which the substance was obtained on concentration. When crystallised from acetone i t melted a t 160O.The yield was 14 grams (Found C=66*1; H=3.8; S=28*5. Calc. CI~66.6 : H=3*7; S=29*6 per cent!.). 9 10-Diphenyl-9 lO-diltydroniLtlzmcene.-The catalyst was pre-pared from 1 gram of aluminium 20 grams of mercuric chloride, and 15 C.C. of benzene. Six C.C. of chloroform were added drop by drop through the condenser and the flask was allowed to remain a t the ordinary temperature for two hours and then heated for an hour a t 40° and then for another hour a t 40-50°. On cool-ing the product was decomposed with ice and filtered. There separated from the filtrate a deep red oil from which some un-changed benzene was evaporated. The residue was extracted wit 1335 RAY MODIFICATION AND EXTENSION O F THE boiling acetic acid containing a little water from which the com-pound separated on cooling.After being crystallised from dilute alcohol and then repeatedly from dilute acet,one the compound melted at 159O (Linebarger Amer. Chem. J. 1891 13 556 gives 164.2') (Found C=93*2; H=6-7. Calc. C=93*9; H=6*1 per cent.). The same compound was obtained by the interaction of 3 C.C. of benzylidene chloride 8 C.C. of benzene 0.5 gram of aluminium, and 10 grams of mercuric chloride the reaction being completed a t 50-55O. The product was isolated as described above (Found: C =34.0; €1=6*39. Calc. C= 93.9; H=6*1 per cent.). A solu-tion of 1 gram of the substance in acetic acid was oxidised with an acetic acid solution of chromium trioxide and the product poured into water. The resinous mass was dried and then sublimed and the sublimate was proved to be anthraquinone by the method of mixed melting points.The diacetyl derivative was prepared by heating 1 gram of the substance with 10 C.C. of acetic anhydride and four drops of pyridine under reflux for an hour. The product was poured into water and neutralised with sodium carbonate. The viscous mass solidified and after being fractionally crystallised from dilute alcohol melted a t 9 2 O (Found C=85*3; H=7*4. C28H2402 requires C=85-7; H=6-8 per cent.). condensa-tion was performed as in the preceding case the catalyst being prepared from 1 gram of aluminium 20 grams of mercuric chloride, and 15 C.C. of toluene. Chloroform (1 mol. for 2 niols. of toluene) was added through the condenser and finally the reaction was completed a t 70°.The oily product obtained after the decompasi-tion of the mixture with ice after being freed from chloroform and toluene solidified when kept in a vacuum desiccator and when crystallised from dilute acetic acid melted a t 2 1 5 O (Found: C=92*0; H=7-9. catalyst , prepared from 8 C.C. of toluene 0.5 gram of aluminium and 10 grams of mercuric chloride was treated with 4 C.C. of benzyl-idene chloride the reaction being completed by heating at 60-70° for two hours. The oily product obtained after the usual treat-ment was dried and distilled under diminished pressure when some oily matter passed over and the residue solidified. This was extracted with hot alcohol and on concentration a product was obtained which after crystallisation from acetic acid melted a t 1 8 5 O (Found C= 92.8 ; H = 7.0.C&H2* requires C = 93-3 ; H = 6.7 per cent.). Dimethyl-9 10-ditolyl-9 10-dihydr0anthracene.-This C,H2 requires C=92.7; H=7.3 per cent.). Dime t hyl- 9 10 -dip heny l-9 1 0-di hydroaltt hracene .-Th FRIEDEL AND CRAFTS' REACTION. PART I. 1339 9 9 10 10-Tetraykenyl-9 lO-dih?/cEroulLthrucenf:.-Eight C.C. of carbon tetrachloride were added to the catalyst prepared from 20 C.C. of benzene 1 gram of aluminium and 20 grams of mercuric chloride and the whole was kept a t 50-60° for two hours and then at TOo for an hour. After decomposing the product with ice and filtering the dried residue was extracted with carbon disulphide from which some of the tetraphenyl derivative was obtained.The filtrate separated into two layers and the benzene layer on evaporation gave a further quantity of the substance, which when crystallised from dilute acetone melted a t 159' (Found C=94.0; H=6*8. C,H requires C=94*2; H=5*8 per cent.). The same compound was obtained by adding 5 C.C. of benzotrichloride in the course of half an hour to the catalyst pre-pared from 15 C.C. of benzene 1 gram of aluminium and 20 grams of mercuric chloride. The product isolated as above melted at 169O (Found C=94*02; H=5.1. Calc. C=94-2; H=5*8 per cent.). o-Nitrotriphen?/lmethane .-Five C.C. of chloropicrin were used with 20 C.C. of benzene. The mixture was warmed first in a tepid-water bath and then for a few hours at 45O. The product was decomposed with ice distilled in a current of steam and the resi-due filtered dried and extracted with much boiling alcohol. This, on concentration deposited o-nitrotriphenylmethane which on recrystallisation from alcohol melted and decomposed a t 145' (Found C=78*49; H=5.54; N=4.5. Calc. C=78*8; H=5*1; N = 4.8 per cent.). I n conclusion I wish t o express my best thanks t o Sir P. C. Rgy for the interest he has taken in the work and to Mr. M. L. Dey for his criticisms and suggestions. CHEMICAL LABORATORY, COLLEGE OF SCIENCE, UNIVERSITY OF CALCUTTA. [Received May 216t 1920.