mix UNIVERSITY OF ILLINOIS May 29 .192. A . THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION BY Harry—. Erana i 3 _ _ ^JCataon entitled The use _o f_ Sulphur M on o_ Chi or i de as _a_ Car rier in the Production of Acid Chlorides IS APPROVED BY ME AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE Bachelor of Science in Chemistry College of Liberal Arts and Science DEGREE OF 500172 . TABLE Off CONTENTS Pages Acknowledgment Preface---- Bibliography and Theoretical Considerations 1-3 Experimental work • — 4-15 Acetyl Chloride Experiment I 4 -5 Experiment II — 5-6 Experiment III — - — — 6-7 Experiment IV — — ~ 7-8 Experiment VI 8-9 Experiment VII - — — — - 9 Experiment VIII — -- — 9-1$) Experiment IX — -- 10 - 11 Conclusion — — ■ — -- — 12 Benzoyl Chloride Experiment XI — — 13 Experiment XII 13 Experiment XIII — - — — — v 13 - 14 Conclusion — 15 Digitized by the Internet Archive in 2016 https://archive.org/details/useofsulphurmonoOOwats PRRPACR The work was undertaken at the suggestion of Professor Adams in order to investigate the practical poss iblilities of the method. Some of the work was done on the problem at Washing- ton, D.C., under the direction of Professor Adams. The investigations were carried out under varing conditions; the practicability of the process being the keynote of ail the work done. The two acid chlorides which were investigated were acetyl chloride and benzoyl chloride. BIBLIOGRAPHY AND THEORETICAL COBSLDLiRATIQNS. A brief account is given in Bulletin de la Societe Chemque 188V, Series A, page 145 of the interaction between SC1 4 and CHgCOgH by V. Auger. The method followed being: A flask in which one mole of S^Clr, and two moles of CHgOOgH was cooled with ice and salt ( tamp era tu res not given). Chlorine was passed into the mixture until no more chlorine was absorbed, when the flask was allowed to warm up to room temperature. The free sulfur compounds were removed by shaking with mercury or copper powder. The mixture was then distilled until a boiling point of 60° was reached. The yield given was 500 grams of acetyl chloride from 600 grams of acid. No mention is made of S0gCl P in the product. SCl^ is only stable at -19° and at higher temperatures an equilibrium exists SC1 4 ; SCI# -h C1 P . It was thought that at 10° to 0° the reaction would probably progress smoothly without too high a formation of of the chlor compounds of the methyl group. The reactions considered were the reaction of SCl /u present in small amounts at 0° to 10° bringing about the reaction 2CH„C0 o H 4- SCI — 2CH C0C1+S0 + 2HC1 O d 4b O d The additional possiblility of the reaction gCH CO H+SC1 4- Cl 2CH 3 C0C1 ^S0 2 +2HC1 was 2 2 2 2 considered. , I . -a- Many patents have been taken out for the production of (GHgGOjgO from CH^COQITa and S^Cl^ Cl^. See Chemical Society Transactions 1909, p. 1235; 1913 p. 1361- Die Berichte 1884 p. 1286, also Thorpes Dictionary of Applied Chemistry: Acetic Anhydride, pages 27 -30, Vol. I, 1921 Edition. The interaction of SO Cl -f CK GO Ja for production of d* d O dt CHgCOgUa is quite well known. A working application being given in German Patent ss6, 218, 1907. The reaction being carried out at 20° and is as given 2CH COONa -h SO 0 C1 0 — 2CH C0C1 -f- 2EaCl S0 o . In the presence of an excess of CEgCOglla acetic anhydride is formed. CHgCQQl'Ts -t CEgCOCl (GHgCOjg-t- EaCl In all trie reactions employed for the production of acetic anhydride using either the S^Clg or the oxychlor compounds GH^GOGl is an intermediate compound. Reasoning from analogy if CH„GQ H were used it should d) dj yield a high yield of CEgCOCl and a very little Acetic ari&ydride. This reasoning proved correct as is shown in the experimental work. The production of benzyoyl chloride by the use of SgClg and Clg was investigated as a similar case. The low rate of activity found in the chlorination was probably due to too 107/ temperature, the gum like substance v/as a sulfur organic compound such as are discussed in Journal of the Chemical Society 1913, page 1861. The type of compound which is unstable , t - 3 - is (0511500)22 . As mentioned in the Experimental notes this gum like substance was always formed and disappeared on standing . EXPERIMENTAL v/ORK Experiment I. A round bottom one liter flask fitted with a three- hole rubber stopper v/as used. A glass tube conducted the chlorine into the mixture, the other tube was provided for the escape of HG1; a thermometer was placed in the third hole. Rive moles of glacial acetic acid, three fourths mole of sulfur monochloride were used. Chlorine v/as conducted into the mixture at 10° for eighteen hours, over a six day period; considerable excess chlorine was used. It v/as noticed that the red color of the SClg v/as discharged upon the solution standing and reappeared upon leading chlorine into the mixture again. At the end of the chlorination the mixture v/as of a light yellow color. The fractions (not weighed) were: 1 st 40 - 59° 2nd 60 - 120 3rd 120 - 140 4 th 140 - 155' S Cl was found in fraction two and three. The method 2 2 used being pouring a few drops of the liquid in ice water in which case free sulphur floats as a film. In later experiments the darkening of a bright copper wire v/hen dipped in the liquid was the test generally used. An accident rendered auantative results worthless. ■ , . -5— The boiling points of the possible compounds are: Monochloracetyl chloride 50.9° ilonochloractic acid 106° Dichloracetic acid 135-137° Trichloracetic acid 195° Dichloracetylehloride 107 - 108 Acetic anhydride 137.9° Sulphurmonochloride 138° Sulphur cLi chloride 59° Sulphurylchloride 69.2° Experiment II The light was screened from the chlorination flash in this experiment in order to ascertain if light was the catalyst which caused the d6colori2ation of the mixture on standing. The mixture used was 3 l/E moles of GKgCOgHand l/£ mole of S^Clo, the temperature 8° - 10°. Chlorine was passed into the mixture for 16 hours over an interval of four days. The decolorization (due to SCI ) was not prevented by excluding the light • The mixture was fractionated in a two bulb column. The fractions were: 1 st fraction 40 - 60° 195 grams 2 nd ’ ' 60 - 119° 46 grams i » Tar-like residue 50 . . * - 6 - The first cut on the basis CHgCOCl theoretical yield, showed a yield of 125 fo; the SGgCi^ found in the distillate e explained the overrun. The presence of SOpClg shown by pouring the mixture in H 2 °: SO^Clg 2HgO H 2 £0 4 HC1 The HrjSC^was proven by BaCl^. Exp er iment III. The possiblility of an interaction between SOgClg, SGlg end CH^COgH was studied. The hypothetical equation is 2 GHgCO^H d- S0^G1^4- SClg V 2 CHgCQCl-*- 2S0g-*-2HCl Three and one half moles of GH a GO-,H and one half mole 5 2 of SgClg were cooled to zero and saturated with Gig, one mole of SOgClg was then added and the temperature allowed to rise to room temperature. After standing for thirty hours it was again distilled. The following cuts were made: Eirst fraction 40 - 55° 106 Second ' 1 55 - 75° 109 Third 1 ' 75 - 118° 55 fourth 1 ' 118 - 188° 55 Residue 68 ■ * ' -7- A large portion of cuts one and two proved to be SO^Cl^. Gonolusi on : Under the conditions of the experiment the interaction between S^Clg ^E^CO^E °ceured to only a slight extent. Experiment IV This experiment was made to determine the quality of the product formed when a large amount of SOI4 was present. Three and one half moles of CH„C0 o H and one half mole of 3 c SgClg were cooled as rapidly as possible without freezing out too much acetic acid down -19°. It was possible to cool down without entire solidification as the eutectic point was lowered by the formation of the chlorcompounds as chlorine was led into the mixture. The final cooling was done with CaCl r Cj and ice. The mixture was saturated with Cl at -19° and left well packed in salt and ice over night to permit the completion of the reaction. SCI4 -f- 2 CE3CO2H — 2 CH3CO01 2EC1 -+-S02 The next day the mixture was again cooled to -17° and saturated with Cl . The mixture stood for 24 hours and was Cj distilled. Eirst Gu t 45° - 80° 133 grams 35,1 of the material boiled between 45 - 60°. No SgClo was found in the distillate. Large amounts of SO^Cl^ were given off in distillation. 1 - 8 - Second Gut 80 - 123° 42 grams Ilinely per cent boiled between 118° - 120°. Weight of escaping gas and loss 50 grams Weight of fractions dnd residues recovered 290 grams. A test was made on the third fraction by oxidizing with KNOg under a reflux, and HgSO^ was formed proving the presence of or- ganic sulfur in this fraction* Experiment VI This experiment was made to obtain additional data regarding the possible reaction: 2CH 5 G0 2 H f SO 2 C1 £+SCl 4 — h 2CiigC0Ql f 2S0g 4- 2HC1 One fourth mole of S^Clg and one half mole of SOgClg were saturated with Gig at 0° to -6° in order to change SgClg to SClg. Three moles of CH^CQ^H was then added, the mixture was o 2 allowed to warm up in an ice salt bath to room temperature in twenty- four hours. It was again saturated with Gig at Oo- 6° and left for twenty hours as before. SgGjlg and SClg were absent in the mixture as shown by test. The mixture weighed 235 grams. Weight of Distillate 40° - 80° 100 grams. 11 11 residue 125 1 ' SOgClg in distillate 59.27 ’ 1 This shows 40.7$ CH^GOCl formed in the first cut. Conclusion : The reaction of SOgClg and SgC^with CHgCOgH is ^illl , - 9 - not a practical one, altho an interesting possibility. Experiment VII This experiment was made to check data at 0° - 15G^ . The mixture used was 3 1/2 moles of CH^CO^H ? i i i ID 3 1 l/2 mole of SgClg The chlorination was carried on in diffused light. A very slow stream of chlorine was led into the mixture. Six hours of chlorination used up the S^Glg* The weight of the mixture was 305 grams The weight of the first fraction 40° - 75° was SO grams 75 - 118° "33 " 1 1 1 1 1 1 1 1 1 1 1 1 Two thirds of the 33 grams came over between 106° - 112° showing the presence of chloracetylchlorides. Third fraction 116° - 123° Acetic acid 68 grams Fourth .Fraction 123° - 150° 53 ' ' The loss due gas and volatility was 69 grams (305 - 236) Conclusion: Under the conditions best suited to a commercial production the experiment shows a poor yield of CH^CQCl and a high formation of undesired higher chlor bodies. Experiment VIII Experiment made to determine the results to be expected at room temperature chlorination. The proportions were the same as in the former experiments, viz: 3 l/2 moles of Ch^GOgH and l/2 mole of ■ ' ' - 10 - Chlorine was passed into the mixture slowly, the chlorination took ten hours, and occupied three days. The finished chlorin- ated mixture was allowed to stand at room temperature connected to a water cooled reflux condenser for twenty four hours to allow the escape of the gasses. It was fractionate: first Cut 0 o 1 CD o o 63 grams Second ' 1 1 o o CO 125° 27 » 1 Third ' ' 125° - 140° 76 i i Residue estimated 50 SO^Cl^ found in first cut 42.1$ Conclusi on: The fractions obtained do not show any very high increase in chloraeetic or chloracetyl chloride at a higher temperature, but the yield of acetyl chloride is very low and tar residue high. Experiment IX This experiment was made to determine the effect of a higher concentration of S Cl over the acetic present in the 2 2 mixture. One half mole of SoClg was used and one mole of glacifl.1 acetic; the mixture was cooled to -5° to -12° while chlorine was passed into the mixture, until the evolution of HC1 slowed down. Then l/2 moles of additional CH^CO^H was added and Cl . - 11 - pass e& in until the HG1 given off became noticeably less, when another l/2 mole of Cl CO H was added. Unpon standing over 3 2 night the SClg color was completey discharged. The mixture was fractionate: First Fraction 30° - 75° 186 grams Second 1 ' 75° - 118° 8 ' ’ Third Fraction 118° - 125° 11 Fourth ' ' 125° - 140° not weighed Fifth ' 1 140° - 175° 22 grams Residue tar The fifth fraction gave a yield of 10 grams of monochlor acetic acid. The first fraction was again fractionated in a column, 177^ grams being taken. First Gut 35 - 55° 126 grams Residue in distilling flask 28 gr ams 154 1 * Loss due to gas given off and volatility loss from the receiver 23 grams. The fa SQgGlg in the 126 grams cut was 37.2 > 0 — 36.9 % This shows an indicated yield of 53.6 fo CEgCOCi on theory of CH^COgH. Gonclusi on: This experiment shows the most interesting possiblili ties for the production of CH^COCl from But the high 'fo of SO^Cl^ makes the product obtained valueless. I - 12 - C on elusion In as much as the problem was one in which the interest was largely in the practical possibilities of using S^Gl^ rather than PQl^ as a chlorine carrier to produce acetyl chloride, it was proven impractical. The yield of acetyl chloride in Experiments IV and IK are such as to male it profitable to produce acetyl chloride in this manner, provided a method may be devised to easily and cheaply remove the SO Cl from the product. Experiment 2 £ IV is of much less value as a practical method, owing to the low temperature at which the reaction was carried on; this objection does not hold for Experiment IK. . -13- Exp e rimen t XI The chlorination of Benzoic Acid to Benzoyl Chloride, The chlorination was done at room temperature. Three hundred and fifty c.c. of CC1 was used as a solvent, or dilutent into which was charged 1££ grams of benzoic acid (one mole) and i/3 mole of S^Cl^* The equation of the desired reaction being: co 2 e V -CQCl + S £ C1 £ ^ 3D1 £ -+ 4HC1 2S0, The rate of chlorination was very slow; many troublesome stoppages of the chlorination tube was caused by a gum-like deposit which formed in and about the inlet tube. After several at tents the experiment was discontinued. Experiment XII This experiment was also made using CC1 4 as a dilutent sovent, 350 c.c. being used. The benzoic acid was added in small portions in order to prevent the fomation of the gum- like material. After 17 grams had been added the gum- like substance prevented further admission of Cl . Very little HC1 was given off at the time and evidence showed very little chlorinati on. Experiment XIII The solvent dilutent chsen in this experiment was benzc^l -14- chloride, as it was thought that the presence of the benzoyl chloride might act as a catalyst. One hundred and thirty- seven grains of benzoyl chloride and l/8 mole (17 grams) of SgClg were placed in the flask; the benzoic acid was added in ten-gram portions during an interval of eight days# The ab- sorption of chlorine was veiy slow. Tho time during which chlorination was extended was thirty- four hours, chlorine being conducted into the solution for this time. The disappearace of the benzoic acid from the mixture was taken as an indication of its chlorination. Sixty grams of benzoic acid were used. The mixture was distilled, a large amount of HG1 being given off, up to 150°. ITirst fraction 190°- 195° weighed 109 grams Second 1 1 195°- 205° 1 1 56 grams Tar- like residue 53 11 Deducting the original amount of benzoyl chloride added the yield was 28 grams or 43.4$ of the crude material. Boiling point Benzoyl chloride 199° Boiling point Benzoic anhydride 360° , - 15 - Conclusi on The chlorination of benzoic acid at room temperatures using SgClg as a carrier is not a practical tiling. The Experiment XIII showed the yield and the very slow rate of chlorination to make it an unprofitable thing under the conditions of the experiment. Other lines of research were taken up and the possible chlorination of benzoid acid using SgClg as a carrier at higher temperatures was not tried.