Brigham Young University BYU ScholarsArchive Theses and Dissertations 1947-04-01 The preparation of certain organic chloroformates and carbonates Robert E. Brailsford Brigham Young University - Provo Follow this and additional works at: https://scholarsarchive.byu.edu/etd BYU ScholarsArchive Citation Brailsford, Robert E., "The preparation of certain organic chloroformates and carbonates" (1947). Theses and Dissertations. 8175. https://scholarsarchive.byu.edu/etd/8175 This Thesis is brought to you for free and open access by BYU ScholarsArchive. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. THE PREPARATI OH OF CERTAI N 0RG.1NIC CHLOROFORJ.'\Ll.TES AND CARBON T Thesis ubmitted to the Department of Chemistry Brigham Young University ~ .. ... "') .~ . ~ . "'). ... .. .. .. .. , ... .. ... : : ....: . ..-. ~ ..·.: : ..: ...• : ·.. ~ . : ,.. .~ : :. : ·: : ··.... ; ~ : ·. : : .: . : . : : : ••• .... •." •,.r_·: -••• ~ .... In Parti a l Fulfillment of the Re~uirements for the Degree Master of cienoe 147143 by Robert E. Brailsford .tipril 1947 This Thesis by Robert E. Brailsford is accepted in its present farm by the Department of Chemistry of Brigham Young University as satisfying the ·rhesis requirement for the degree of Master of Science. PREFACE flhile working for the Hooker Electrochemical Company of Niagara Falls , New York , from April 3 , 1943 , to January 30 , 1946 , the writer became interested in organic chloroformates and. carbonates , an interest instigated by requests from B. F . Goodrich Company for a number of samples . fter returning to Brigham Young University that preliminary interest was revived and the experi - mental work of this thesis was performed. under the direction of Dr . Charles ' . :Maw and Professor Joseph K. Nicholes . The writer wis hes to thank these men and Dr . Loren C. Bryner for their kind assis tance in proof readin g this thesis and offerin g numerous suggestions for its improvem ent . TAELE OF CONTENTS Page I 1'TRODUCTI ON • • • • • • • • • • • • • • • • • • 1 1 CARBONYL CHLORIDE , PREP_ RA.TIOU AIID USE • • • • • 2 HI ST RY, PREP}1.R.nTION, AlID .. OP:ERTIES OF TH · ORG m:c CHLOROFORMATES~ ND G RBOILTE • • • • 5 OTHER ·:ET HODS OF PREP A!w.TI ON • • • • • • • • • • 14 USES • • • • • • • • • • • • • • • • • • • • • • 16 EXPERI1 ":NTAL ' ORK • • • • • • • • • • • • • • • • 18 m. ARY • • • • • • • • • • • • • • • • • • • • • • 25 LITERATURE CITED • • • • • • • • • • • • • • • • 29 PPElillIX Table I. hysical Const an ts of Known :Mono- Chloroformic Esters Table II . Physical Const ants of Known Organic Carbonates Table III . Prepared Organic Carbonates Fi g ure I . J ..ppara tus Utilized INTRODUCTION The preparation of organic carbonates and formates was of considerable laboratory interest during the latter part of the nineteenth century; , but no practical use was made of them. It has now been revived by industrial companies such as t-he :a. F. Good.rich Company and the Hooker Electroahemioal Company. These companies are interested primarily in finding new compounds which can be utilized as intermediates or plasticizers in the plastic and rubber industries. At the present time the primary concern is with the organic chloroformates, which are prepared by the same method as are the carbonates but at a lower temperature. In 1945 the Goodrich Company developed a use for allyl ohlorofo.rmate. This company called upon the Hooker Company to devel op a practical method for preparing and furnishing them with this compound . This problem was accomplished by Edward Belmore , a chemical engineer, in cooperation with the author. 1 Some further work was done upon two or th.ree of the well known aliphatic carbonates. 2 1 Belmore , Edward , and Brailsford, Robert , The Preparation of Allyl Chlo.roformate, a Research Pap~fo.r the Hooker Electrochemical Company, Patent Pending . 2 Work by the ant ho.r under the direoti on of Dr. B. Wojcik , Hooker Electrochemical Company, 1945. 2 Upon returning to Brigham Young University; the author decided to continue this research on org anic ohloro- f'ormates and carbonates for a master's thesis. There are very few organic aromatic carbonates mentioned in the literature. This gave added interest to oontinue the research. The organic chlo.rofo.rmate s are colo.r •less, llnpleasant smelling liquids and ,• f'or the most part, very strong laomymators due to their chlorine content and ease of hydrolysis. The carbonates, on the other hand , are very agreeable smelling liquids or crystalline solids. 3 C_RBONYL CHLORIDE,PREPARATION AND~ The present disoove.ry and industrial preparation of' organic chloroformates and org anio carbonates waited upon the discovery and knowledge of how to use carbonyl ohlo.ride. In 1812 Sir Rn.mph.ray Davy first prepared carbonyl chloride by exposing a mixture of carbon monoxide and chlorine to light: 4 Cl / co 0 = C + - 'Cl 3 Fieser, Louis , and Fieser , Mary, Organic Chemistry (Boston: D. C. Heath and Company, 1944), pp. 178-9. 4 Ibid. 3 This reaction is reversible . At 800° C the phosgene is broken d~1n into its components . 5 Davy gave carbonyl chloride its common name phosgene beaause of its prepara - tion by the influenoe of light (phos , Greek - -light; gene.re , Latin - -born} . 6 Phosgene is still manufactu..red by Davy ' s method using activated charcoal as a catalyst . On a small scale phosgene can be made from carbon tetrachloride and eighty percent pyr,osulfurio aoid ; 7 -,- --- COClz + Pyrosulfuryl chloride is the by- product . This method was used during the war years of 1914 - 18 in Italy and France but was later abandoned in favor of the synthesis from carbon monoxide and chlorine; the method used in Germany . A high yield of phosgene is obtained , but much chlorine is consumed . 8 In the laboratory , phosgene is readily prepared by the oxidation of chloroform with cb.r omic acid mixtu..re: + 30 2COClz + HzO + Cl2 5 Karrer; Paul , Organic· Chemistry (New York: Nordeman Publishing Company, Inc .; · 1938); pp . 203-4 . · 6 Fieser ,·, Louis , and Fieser , Mary; 2.£.• cit ., p . 178 . 7 Whitmore; F~ank., Or,anio Chemistry (New York: D. Van Nostrand Company; Inc ., , 1942 , pp . 516-7 . 8 Sartori, Mario , The War G~ses (New York: D. Van Nostrand Company, Inc ., 1939,p. 62. 4 Chlorine ancl ohloroform contaminate the phosgene prepared by this method. 9 Chloroform is oxidized to phosgene to some extent by the air in the presence of light. This is one reason why chloroform as an anaesthetic has been largely abandoned . Phosgene is a poisonous , suffocating gas at normal temperatures.· It is about ten times more toxic than chlor- ine as a lung injurant. It has an odor that resembles that of mouldy hay. It boils at a° C and fumes in air if moisture is present , due to hydrolysis with the formation of carbon dioxide and hydrochloric acid .l o H 0 = COClz + 2 + 2HC1 Because of its poisonous character and the ease with whi~h it can be prepared , liquefied, and transported, phosgeneI proved very effective in World War .I. Introduced by the Germans in 1915, it was loaded in shells and bombs which exploded upon striking the ground . It was responsible for approximately eighty percent of the gas casualties of the War, for even though it is inh aled deeply, there are no warning symptoms for as long a period as two hours . Injurious physiologioal action in the body is due to the hydrochloric acid formed by hydrolysis of the phosgene . ~ i'irrer , Paul , ~- cit., p . 204 . 10 Ibid. 5 Cl , - Phosgene, C-0, is the acid chloride of carbonic Cl ,. aoid, HO,C:::-0 reacting similarly to other acid chlorides HO " - ' with water , alcohols, amines , etc. which contain active hydrogen. 11 It also reacts readily with dimethylaniline to give Miohler ' .s ketone, an important intermediate in the makin g of triphenyl methane dyes, as is illustrated by the following eg_uation:1 2 -I- = This commercial use far phosgene increased the quantity of the gas , making it available as a war gas. HI STORY, PREPARATION, 1~ PROPERTI~S OF THE ORG.b.NIC CHLOROFOR1\rIAT7fil AND CARBO 1 T'.iES fte~ the preparati on of phosgene by Davy in 1812 chemists beg an to use it to treat a variety of different compounds. In 1833 Dumas treated ethyl alcohol with this gas and obtained ethyl chloroformate:1 3 COC12 + = + HCl 11 Reid, E. Emmet, College Organia Chemistr~ (New York: D. Van Nostr and Company, Inc., l93l), pp . 27 -so. 12 Sartori, Mario, ££• cit., P • 62. 13 Bernthsen , A., A Textbook of Orean ic Chemistrl (New York: D. Van Nostr anu Company, Inc., 1931) ,, p . 289 . 6 This aompound was found to be a volatile liquid with a very disagreeable pungent odor . The physical p~operties of the known mono-ohloroformio esters are recorded in Table I ; those of the carbonates , in Table II . T.he reaction vf.i.th an a lcohol can be conducted in two stages , and either the above mentioned mono or the dialkoxy derivative can be prepared by the proper adjustment of the proportions and the reaction conQitions . 14 In preparing the chloroformates phosgene is used in excess , ana the reaction takes place in the cold . At higher temperatures and with the alcohol in excess the chloroformate fir st formed reacts to form the carbonate : = + HCl Phosgene reacts similarly with aromatic alcohols and :phenols . wli th one molecule of phen ol and one of :phosgene phenyl chloroformate is formed : + a1coc1 + HCl with two molecules of phenol , diphenyl carbonate : 15 14 Sartori , Mario , £2.• oit ., pp . 70- 71 . 15 Ibid- . 7 + ClCOCl + + HCl During the first , orld War a research p.r cg.ram was instigated to pr ot ect troo ps against ph osge n e poisoning . This research resulted in the discovery that it reacted with sodium :phen ol ate to f o.rm diphenyl carb onate . Sodium phenolate placed in the filters of the gas masks furni shed excellent pr otection •16 The first series of compounds formed by the reaction between ph osgene and alc ohols , the ohloroformate s , have a mixed nature .