2756 TMERRY SULPHUR COMPOUNDS REMOVED FROM CCCLXXVII1.-Sulphur Compounds Removed from CL Persian Petroleum by Means of Sulphuric Acid. Part I . By EDWARD HENRY THIERRY. MABERY and SMITE (Amer. Ckm. J. 1891 13 232) isolated several organic sulphur compounds from a crude Ohio oil and established the presence of a series of dialkyl sulphides. Mabery and Quayle (ibid. 1906 35 404) obtained very different results during an investigation of a Canadian petroleum a series of saturated cyclic compounds named thiophanes of the empirical composition C,H,S being isolated; the actual compounds ranged from C,H,,S to C,,H,,S and a derivative of the substance C,H,,S also was prepared (see also von Braun and Triimpler Ber. 1910 43 543; Trochimovski J . RUM. Phys. Chem. SOC. 1916 48 880).More recently other workers have described the isolation and identi-fication of thiophen and its homologues in shale oil. The product now investigated was a sulphuric acid sludge from the rehing of Persian petroleum kindly supplied by Mr. Kewley of the Asiatic Petroleum Co. The oil that separated on dilution was carefully fractionated and of the twenty-nine fractions boiling below 120"/125 mm. four have been investigated. Three of these con-sisted essentially of methyl ethyl sulphide tetra- and penta-methylene sulphides. The fourth fraction was a mixture. It contained a compound C4Hl0S; this was not diethyl sulphide but sdlicient material was not available to determine whether it was methyl propyl sulphide or methyl isopropyl sulphide. All the fractions had an intense odour but the purest samples of the cyclic sulphides mere in no sense objectionable.The various compounds have been characterised by the preparation of a number of deriv-atives such as sulphonium iodides and double salts with mercuric salts. E X P E R I M E N T A L. The dark supernatant' oil obtained by greatly diluting the sulphuric acid sludge (12 litres) with water was shaken with sodium hydroxide and dried over sodium sulphate ; a filrther quantity was extract'ed from the diluted liquid with chloroform the total yield being 1800 C.C. The oil was distilled and the more volatile portions were fractionated five times at a pressure of 760 mm. ; the fractions obtained were (1) below SO" 0.5 c.c.; (2) 59-64' 90 c.c.; (3) 50-89" 8 C.C. ; (7) 89-92" 11 ex.; (8) above 92" 7 C.C. 6468' 11 c.c.; (4) 68-70' 33 c.c.; (5) 70-SO' 10 c.c.; (6 A PERSIAN PETROLEUM ETC. PART I. 2757 The oils boiling above 100"/760 mm. were fractionated eleven Table I shows the degree of separation achieved. times at 125 111111. TABLE I. Fraction. B.p./125 mm. C.C. Fraction. B.p.1125 111111. C.C. 9 up t o 60" 4 20 90-93" 30 10 60-63 12 21 93-96 12 11 63-66 20 22 96-99 9 12 66-69 3 23 99-102 19 13 69-72 5 34 102-105 28 14 72-75 6 25 105-108 16 16 75-78 10 26 108-1 11 14 16 78-81 70 27 111-114 35 17 81-84 75 28 114-117 20 18 S A 8 7 10 29 117-120 18 19 87-90 3 Residue (to be examined) Fractions 4 7 11 and 17 have been carefully examined. Fraction 4 contained 61y0 of chloroform. No satisfactory analysis was possible but the remaining liquid contained about 34.6y0 S.On shaking with mercuric iodide decanting and evaporating in a vacuum pale yellow crystals were obtained which dissociated very rapidly in the air and softened at 59" (Smiles J. 1900 77 164, gives m. p. 59' for CH3*S-C,H5,HgI,). The liquid (2 c.c.) reacted briskly with methyl iodide (1 c.c.) and mercuric iodide (excess). After 3 minutes the product was washed with ether and crystallised from aceton-ther; it then formed fine yellow needles m. p. 86" [(CH,)&IC,H,,Hg12 has m. p. 86" ; Smiles loc. cit.]. white crystals of methyl ethyl sulphide mercurichlmde were immediately precipitated on addition of alcoholic mercuric chloride to the liquid. Several crystallisations from acetone and water gave rather unstable crystals m.p. 101-102". Most of the mercurihalides here described are unstable and were purified with difEiculty immediately beginning to lose sulphide on exposure to air; the ultimate analyses therefore were unsatb-factory. Sintering frequently occurs during melting-point deter-minations and this together with the tendency to dissociate makes trustworthy observations difficult to obtain. Fraction 7 contained 0.5% of chloroform. The analytical Sgures found (C 56.4; €I 11.0) differ from those required for diethyl sulphide (C 53.3; H ll*lyo) but consideration of the resulta obtained with fraction 11 makes it very probable that the divergence in both cases is caused by admixture of about 6:h of a hydrocarbon, b. p. 100-105". The mercuri-iodide prepared as described under Fraction 4, formed unstable pale yellow crystals which did not soften below 100".The methylsulphonium iodide mercuri-iodide formed pale yellow crystals which melted at 54" after repeated crystallisation 5 A * 2758 THIERRY SULPHUR COMPOUNDS ETC. from acetone-ether and the mercurichloride unstable white needles which melted a t 68" after repeated crystallisation from acetone by cautious addition of water. Smiles (J. 1900 77 164) gives 52" as the m. p. of (C,H5),S,Hg12 and 67" as that of (C&€,),(CH,)SI,HgI, whilst for (C2H5),S,HgC12 Loir (Annden, 1853 87 369) records m. p. 90" and Abel (H. 1895 20 269) m. p. 119". These results indicah clearly that the compound is not diethyl sulphide. No addition compounds of the above types of the methyl propyl sulphides have been described.Fr&ion 11 was refractionated and the largest fraction b. p. 64-65"/125 mm. was examined. The liquid boiled at 120-121'1 760 mm. (Found C 56-6; H 9.8; S 34.0%). Diisopropyl sulphide (C 61.0; H 11.9; S 2701%) boils at 120-5"/763 mm. (Beckmm J . pr. Chem. 1878 17 459) and tetramethylene sulphide (C 54.5; H 9-1; S 3603%) at 119" (von Braun and Triimpler Ber. 1910 43 549). The divergence from the values for tetramethylene sulphide may be ascribed to the presence of a little hydrocarbon since derivatives were obtained in a pure state with comparative ease. The methiodide prepared in the usual way crystallised from alcohol in fine white needles decomp. 185-190" (Pound I 54.6. C,H,,IS requires I 5502%). The mercurichloride crystallised from acetone-water had m.p. 126" (Trochimovski loc. cit. gives m. p. 124-5-125.5"). Tetramethylene alphide mercuri-iodide, prepared in the usual way separated from acetonewater in white cry&ak~ m. p. 58". T'etr~m'eth~lenemeth~~lp~nium iodide rnercuh-iidide prepared as previously described formed yellow cryatals, m. p. 111". Fraction 17 was refractionated four times ; the largest fraction had b. p. 83-84"/125 mm. and 138*5"/742 mm. (Found C 58.5; H 9.8; S 31-3. Calc. for C,H,,S C 58.8; H 9.8; S 31*4%). Low results for sulphur were obtained unless oxidation was carried out for 15 hours at 180" and then after the pressure had been released for 10 hours at 250". In estimating the carbon and hydrogen the best results were obtained by weighing the liquid in a small bubbler which was then fixed to the end of the combustion tube the passage of the oxygen causing steady evaporation.It seems certain that the compound is pentamethylene sulphide (compare von Braun Zm. cit.). The mercurichloride was prepared, and crystallised from benzene. Pentamethylenemethylsulphonium iodide prepared in the muid way was converted into the sulphonium base by means of silver oxide; the solution was exactly neutralised with hydrochloric acid and gently evaporated to small bulk. The crystalline sulpbniur CONDEXSATIONS OF SODIUM D E R I V A ~ S m. 2759 c u d e obtained on cooling was precipitated from alcoholic solution with ether washed with acetone and dried in a vacuum over sulphuric acid. The white crystals thus obtained dissociated without melting on heating and decomposed slightly on long standing (Found C 46.7; H 8.7; Cl 22.85.C6H,c1s reQnires C 47.2; H 8.6; Cl 23.3:/,). Pentamethylene sulphone was obtained in very small yield by oxidising the sulphide (2 g.) with excess of permanganate solution; it crystallised from benzene-light petroleum in white plates m. p. 98". Pentamethylene sulphide mercuri-iodide prepared in the usual way, waa washed with ether and crystallised from acetone by cautious addition of water. The white crystals obtained m. p. 72-74", dissociated completely within a few hours when exposed to the air. The mercurichloride separated from benzene in white crystals m. p. 135-136" (Trochimovski gives m. p. 137.5"). The cUorophtinde was obtained by adding a few drops of the sulphide to a strong aqueous solution of platinic chloride; the yellow crystals that separated after a few hours were crystallised from acetonewater. [Found Pt 35-4. (C,H,&),PtCl requires Pt 36.4%]. Perdu-methylenemethylsuZphonium iodide mercuri-iodide prepared aa previously described separated from acetone-ether in yellow cryatals m. p. 78". Trochimovski (Zoc. cit.) gives m. p. 98-5-99". The author expresses his thanks to Professor Donnan for suggesting this work and to Professor Collie and Dr. Brads for valuable advice given during its progress. THE RALPH FOSTER LABORATORY OF ORGANIC CHEXXSTRY, UKIVERSITY C0IJ;EOE. [Received February 26th 1925.