162 CHALLENGER JINKS AND HASLAM THE SULPHUR XXV.-The S'ulphur Compounds of Kimrneridge Shale Oil. Part I. By FREDERICK CHALLENGER JAMES RICHARD ASHWORTH JINKS , and JOHN HASLAM. THE oil obtained on distillation of the Kimrneridge shale of Dorset is characterised by a very high percentage of sulphur which is stated to be 5-8% of the crude oil.* This has prevent,ed its use * References to other shale oils rich in sulphur are given by Demesse and Reaubourg Bull. SOC. chim. 1914. [iv]. 15 625 COMPOUKDS OF KIMMERIDGE SHALE OIL. PART I. 163 as a fuel and although many attempts have been made to remove the sulphur compounds these have been unsuccessful excepting perhaps the recent hypochlorite process of Dunstan. The mode of combination of the sulphur has remained unknown (Perkin J .Inst. Pet. Tech. 1917 3 227; Manfield Zoc. cit. 1916 2 164; Craig and others Zoc. cit. 1915 4 149). Through the kindness of Mr. W. Hardy Manfield who supplied us with several gallons of the crude oil we have commenced an investigation with the object of identifying some of the sulphur compounds. The question of removing them on a commercial scale has not been considered. The only communication which contains any real information as to the ingredients of this shale oil was made by Williams (J. 1855 7 97) who only examined the bases which are sulphur-free. The peculiar odour of the oil seems to be due tlo these pyridine bases and to unsaturated hydrocarbons. I n a typical experiment 3 litres of the crude oil were distilled with steam until practically no more came over.The pale yellow oil (900 c.c.) was separated," shaken with 200 C.C. of dilute hydro-chloric acid (1 to 3) again separated and the process repeated with 100 C.C. of the acid. The mixture was shaken for an hour and left over-night. The separated oil was shaken for an hour with 150 C.C. of 10% sodium hydroxide dried over sodium sulphate, and fractionated three or four times a t 15 mm. The table shows the fractions obtained and some anaiytical results : Sulphur After KaHSO,. B. p. a t befor,- ~. - -/L--Fraction. 15 mm. A'aHSO,. S. C. H. Total. 1 35-50" 10.67 10.83 2 50-70 10.18 10.04 78-84 11.2.3 100.13 19-14 10.04 79.03 ll*OS 100.13 10.04 7s.77 11.09 99.90 3 i0-90 i.12 7-23 4 90-1 10 6-38 6-46 G * 3 9 5 110-130 5.90 6 130-145 7-04 The first two fractions (95 C.C.; 140 c.c.) formed pale yellow oils of pleasant odour which on analysis showed the presence of traces of oxygen. They were therefore separately shaken with saturated sodium bisulphite solution separated mashed and analysed. The bisulphite extracts with sodium carbonate yielded 1 C.C. of ketones, b. p. 130-136" which readily combined with semicarbazide. removed as before and the residue was added t o the main bulk. * The water (9 litres) was extracted with ether bases and phenols were. G 164 OWENGER JMKS AND HASLAM THE SULPHUR After four rectifications of fraction 1 a t the ordinary pressure (no hydrogen sulphide was evolved) fractions were obtained of which the first (b. p. 60-110") contained 14.07 and the last (b.p. above 150°) 7.82:/ of sulphur. On standing for some weeks resin was deposited doubtless arising from olefines or diolefines. On redistillation water was formed and a sharp odour observed prob-ably due to unsaturated aldehydes arising from decomposition of some oxidation product. Removal of Sulphur from Fraction b. p. 60-11Oo.-Five C.C. were slowly added to 25 C.C. of sulphuric acid a t - 15". A dark-red colour developed as with all fractions of the oil. The mixture was well shaken and after 18 hours the oil was separated washed with water and found to be free from sulphur. It gave no indo-phenin reaction nor any colour with sulphuric acid was stable to cold aqueous permanganate and had a strong odour of toluene. After nitration with sulphuric and nitric acids a t loo" the product slowly solidified to white needles containing nitrogen (m.p. and mixed m. p. with 2 4-dinitrotoluene 71"). Oxidation of the Fraction b. p . 50-70"/15 mm.-(a) With potassium pemcanganate. The oil was sealed in a bulb which was added to 200 C.C. of 2% aqueous potassium permanganate and broken by shaking. After 10 hours' shaking and addition of more permanganate till decoloration ceased the solution was filtered, acidified with hydrochloric acid and precipitated with barium chloride excess of permanganate being removed with alcohol : (1) 0.4462 gave 0.2450 BaSO,; S = 7.54. (2) 0.5106 gave 0.2830 BaSO,; S = 7.61. (3) 0.7808 gave 0.4264 BaSO,; S = 7.50. I n (3) the solution was evaporated with nitric acid to remove any oxalates.About 0.5 g. was shaken for 4 hours with 12 C.C. of water and 5 C.C. of fuming nitric acid and evaporated with hydrochloric acid and salt 0.5080 gave 0.2695 'BaSO,; S = 7.28 0.5110 gave 0.2766 BaSO,; S = 7.43. About 75% of the total sulphur is obtained as sizlphuric acid. This would indicate that alkyl sulphides and mercaptans are not a t any rate the chief sulphur compounds present whilst the cyclic polymethylene sulphides also form stable sulphones on oxidation (Trochimovski, J . Russ. Yhys. Chem. SOC. 1916 48 1 880). Identification of 2-n/lethylthiophen in a Fraction b. p . 80-1 loo.-The fraction (11 g.) mercuric acetate (80 g.) and 230 C.C. of water were shaken for 15 hours. The precipitate (36 g.) which contained much mercurous acetate due to the presence of olefines was extracted three times with hot alcohol.The insoluble residue decomposed about 225". 16 G. were distilled with 60 C.C. of hydro-(b) With nitric mid COMPOUNDS O F KIAlMERIDGE SHALE OIL. PART I. 165 chloric acid (I 2) giving about 3 C.C. of a colourless oil. This had a pure aromatic odour and gave a strong indophenin reaction. With excess of bromine water long needles m. p. 86-87" were obtained. Tribromo-2-methylthiophen melts a t 87' but when mixed with the Corresponding 3-methyl derivative non-separable mixed crystals m. p. 74" are obtained (Meyer Ber. 1885 18, 544). 3-Methylthiophen would therefore seem to be absent. 2-nl~lh~Ethiophe~imerczirlchZoride @B,*C,H,S*HgCl.-One C.C. of the regenerated oil was shaken with 10 C.C. of alcohol 100 C.C.of saturated mercuric chloride solution and 30 C.C. of 33% sodium acetate solution. The precipitate (2.6 g.) was free from mercurous chloride.* Rccrystallised from hot alcohol and then from acetone, it had m. p. 194-195" with slight previous sinfering; but when placed in the bath at 190' its m. p. was 202'. Repeated experi-ments gave no depression of the m. p. on admixture with authentic 2-methylthiophenmercurichloride. The compound was converted to niercury 2 2'-dimethyldithienyl (CH,*C41P,S),Hg hy the method of Steinkopf (Annalen 1921 424 49); m. p. and mixed m. p. 160". This was converted by mercuric bromide into 2-methylthiophen-mercuribromide (Steinkopf Zoc. cit.); m. p. and mixed m. p. 178". All these mercury derivatives of thiophen homologues were shown by Steinkopf to sinter slightly before melting.The non-depression of m. p. was however very definite. The m. p. of 2-methyl-thiophenmercurichloride was strongly depressed on admixture with the corresponding thiophen compound. IdentiJication of Thiophen.-Another specimen of the oil purified as before gave fractions b. p. 77-83" and 83-93'. With mercuric chloride and sodium acetate these gave mercurous chloride (due to olefines) and traces of a solid -which on repeated crystallisation from alcohol and acetone gave a strong indophenin reaction and was identified as thiophenmercurichloride by its m. p. and mixed m. p. (180-181"). It strongly depressed the m. p. of 2-methyl-thiophenmercurichloride. The presence of thiophen derivatives in the oil explains its behaviour on oxidation.In some cases Meyer (" Die Thiophen Gruppe," pp. 55 204) obtained very bad yields of carboxylic acids on Oxidation of the alkylthiophens owing to almost complete decomposition. We find that cold 2y0 aqueous potassium per-inanganate completely oxidises thiophen to sulphuric acid although Angeli and Alessandri (Atti R. Accad. Liizcei 1911 [vl 20 i 314) state that it is stable to alcoliolic permanganate. Our results are in general agreement with those of other workers. Scheibler (Ber. 1915 48 1815; 1916 49 2595; 1919 52 1903) * Due to previous removal of olefines with mercuric acetate 166 PRATT AND ROBINSON A SYNTHESIS OF examined shale oils rich in sulphur. His method of purification was very complicated but from a fraction of b.p. 170-180"/360 mm. he obtained with acetyl chloride and aluminium chloride a ketone possibly propylacetothienone C,H,PrS*COMe, and analysed the semicarbazone. Pfaff and Kreutzer (2. angew. Chem. 1923 36 437) identified 2-rnethylthiophen in a fraction of lignite tar by conversion into 2-methylacetothienone. THE UNIVERSITY MANCHESTER. [Received November 20th 1924. 162 CHALLENGER JINKS AND HASLAM THE SULPHUR XXV.-The S'ulphur Compounds of Kimrneridge Shale Oil. Part I. By FREDERICK CHALLENGER JAMES RICHARD ASHWORTH JINKS , and JOHN HASLAM. THE oil obtained on distillation of the Kimrneridge shale of Dorset is characterised by a very high percentage of sulphur which is stated to be 5-8% of the crude oil.* This has prevent,ed its use * References to other shale oils rich in sulphur are given by Demesse and Reaubourg Bull.SOC. chim. 1914. [iv]. 15 625 COMPOUKDS OF KIMMERIDGE SHALE OIL. PART I. 163 as a fuel and although many attempts have been made to remove the sulphur compounds these have been unsuccessful excepting perhaps the recent hypochlorite process of Dunstan. The mode of combination of the sulphur has remained unknown (Perkin J . Inst. Pet. Tech. 1917 3 227; Manfield Zoc. cit. 1916 2 164; Craig and others Zoc. cit. 1915 4 149). Through the kindness of Mr. W. Hardy Manfield who supplied us with several gallons of the crude oil we have commenced an investigation with the object of identifying some of the sulphur compounds. The question of removing them on a commercial scale has not been considered.The only communication which contains any real information as to the ingredients of this shale oil was made by Williams (J. 1855 7 97) who only examined the bases which are sulphur-free. The peculiar odour of the oil seems to be due tlo these pyridine bases and to unsaturated hydrocarbons. I n a typical experiment 3 litres of the crude oil were distilled with steam until practically no more came over. The pale yellow oil (900 c.c.) was separated," shaken with 200 C.C. of dilute hydro-chloric acid (1 to 3) again separated and the process repeated with 100 C.C. of the acid. The mixture was shaken for an hour and left over-night. The separated oil was shaken for an hour with 150 C.C. of 10% sodium hydroxide dried over sodium sulphate, and fractionated three or four times a t 15 mm.The table shows the fractions obtained and some anaiytical results : Sulphur After KaHSO,. B. p. a t befor,- ~. - -/L--Fraction. 15 mm. A'aHSO,. S. C. H. Total. 1 35-50" 10.67 10.83 2 50-70 10.18 10.04 78-84 11.2.3 100.13 19-14 10.04 79.03 ll*OS 100.13 10.04 7s.77 11.09 99.90 3 i0-90 i.12 7-23 4 90-1 10 6-38 6-46 G * 3 9 5 110-130 5.90 6 130-145 7-04 The first two fractions (95 C.C. ; 140 c.c.) formed pale yellow oils of pleasant odour which on analysis showed the presence of traces of oxygen. They were therefore separately shaken with saturated sodium bisulphite solution separated mashed and analysed. The bisulphite extracts with sodium carbonate yielded 1 C.C. of ketones, b. p. 130-136" which readily combined with semicarbazide.removed as before and the residue was added t o the main bulk. * The water (9 litres) was extracted with ether bases and phenols were. G 164 OWENGER JMKS AND HASLAM THE SULPHUR After four rectifications of fraction 1 a t the ordinary pressure (no hydrogen sulphide was evolved) fractions were obtained of which the first (b. p. 60-110") contained 14.07 and the last (b. p. above 150°) 7.82:/ of sulphur. On standing for some weeks resin was deposited doubtless arising from olefines or diolefines. On redistillation water was formed and a sharp odour observed prob-ably due to unsaturated aldehydes arising from decomposition of some oxidation product. Removal of Sulphur from Fraction b. p. 60-11Oo.-Five C.C. were slowly added to 25 C.C. of sulphuric acid a t - 15".A dark-red colour developed as with all fractions of the oil. The mixture was well shaken and after 18 hours the oil was separated washed with water and found to be free from sulphur. It gave no indo-phenin reaction nor any colour with sulphuric acid was stable to cold aqueous permanganate and had a strong odour of toluene. After nitration with sulphuric and nitric acids a t loo" the product slowly solidified to white needles containing nitrogen (m. p. and mixed m. p. with 2 4-dinitrotoluene 71"). Oxidation of the Fraction b. p . 50-70"/15 mm.-(a) With potassium pemcanganate. The oil was sealed in a bulb which was added to 200 C.C. of 2% aqueous potassium permanganate and broken by shaking. After 10 hours' shaking and addition of more permanganate till decoloration ceased the solution was filtered, acidified with hydrochloric acid and precipitated with barium chloride excess of permanganate being removed with alcohol : (1) 0.4462 gave 0.2450 BaSO,; S = 7.54.(2) 0.5106 gave 0.2830 BaSO,; S = 7.61. (3) 0.7808 gave 0.4264 BaSO,; S = 7.50. I n (3) the solution was evaporated with nitric acid to remove any oxalates. About 0.5 g. was shaken for 4 hours with 12 C.C. of water and 5 C.C. of fuming nitric acid and evaporated with hydrochloric acid and salt 0.5080 gave 0.2695 'BaSO,; S = 7.28 0.5110 gave 0.2766 BaSO,; S = 7.43. About 75% of the total sulphur is obtained as sizlphuric acid. This would indicate that alkyl sulphides and mercaptans are not a t any rate the chief sulphur compounds present whilst the cyclic polymethylene sulphides also form stable sulphones on oxidation (Trochimovski, J .Russ. Yhys. Chem. SOC. 1916 48 1 880). Identification of 2-n/lethylthiophen in a Fraction b. p . 80-1 loo.-The fraction (11 g.) mercuric acetate (80 g.) and 230 C.C. of water were shaken for 15 hours. The precipitate (36 g.) which contained much mercurous acetate due to the presence of olefines was extracted three times with hot alcohol. The insoluble residue decomposed about 225". 16 G. were distilled with 60 C.C. of hydro-(b) With nitric mid COMPOUNDS O F KIAlMERIDGE SHALE OIL. PART I. 165 chloric acid (I 2) giving about 3 C.C. of a colourless oil. This had a pure aromatic odour and gave a strong indophenin reaction. With excess of bromine water long needles m.p. 86-87" were obtained. Tribromo-2-methylthiophen melts a t 87' but when mixed with the Corresponding 3-methyl derivative non-separable mixed crystals m. p. 74" are obtained (Meyer Ber. 1885 18, 544). 3-Methylthiophen would therefore seem to be absent. 2-nl~lh~Ethiophe~imerczirlchZoride @B,*C,H,S*HgCl.-One C.C. of the regenerated oil was shaken with 10 C.C. of alcohol 100 C.C. of saturated mercuric chloride solution and 30 C.C. of 33% sodium acetate solution. The precipitate (2.6 g.) was free from mercurous chloride.* Rccrystallised from hot alcohol and then from acetone, it had m. p. 194-195" with slight previous sinfering; but when placed in the bath at 190' its m. p. was 202'. Repeated experi-ments gave no depression of the m. p. on admixture with authentic 2-methylthiophenmercurichloride.The compound was converted to niercury 2 2'-dimethyldithienyl (CH,*C41P,S),Hg hy the method of Steinkopf (Annalen 1921 424 49); m. p. and mixed m. p. 160". This was converted by mercuric bromide into 2-methylthiophen-mercuribromide (Steinkopf Zoc. cit.); m. p. and mixed m. p. 178". All these mercury derivatives of thiophen homologues were shown by Steinkopf to sinter slightly before melting. The non-depression of m. p. was however very definite. The m. p. of 2-methyl-thiophenmercurichloride was strongly depressed on admixture with the corresponding thiophen compound. IdentiJication of Thiophen.-Another specimen of the oil purified as before gave fractions b. p. 77-83" and 83-93'. With mercuric chloride and sodium acetate these gave mercurous chloride (due to olefines) and traces of a solid -which on repeated crystallisation from alcohol and acetone gave a strong indophenin reaction and was identified as thiophenmercurichloride by its m.p. and mixed m. p. (180-181"). It strongly depressed the m. p. of 2-methyl-thiophenmercurichloride. The presence of thiophen derivatives in the oil explains its behaviour on oxidation. In some cases Meyer (" Die Thiophen Gruppe," pp. 55 204) obtained very bad yields of carboxylic acids on Oxidation of the alkylthiophens owing to almost complete decomposition. We find that cold 2y0 aqueous potassium per-inanganate completely oxidises thiophen to sulphuric acid although Angeli and Alessandri (Atti R. Accad. Liizcei 1911 [vl 20 i 314) state that it is stable to alcoliolic permanganate. Our results are in general agreement with those of other workers. Scheibler (Ber. 1915 48 1815; 1916 49 2595; 1919 52 1903) * Due to previous removal of olefines with mercuric acetate 166 PRATT AND ROBINSON A SYNTHESIS OF examined shale oils rich in sulphur. His method of purification was very complicated but from a fraction of b. p. 170-180"/360 mm. he obtained with acetyl chloride and aluminium chloride a ketone possibly propylacetothienone C,H,PrS*COMe, and analysed the semicarbazone. Pfaff and Kreutzer (2. angew. Chem. 1923 36 437) identified 2-rnethylthiophen in a fraction of lignite tar by conversion into 2-methylacetothienone. THE UNIVERSITY MANCHESTER. [Received November 20th 1924.