THE ADDITION REACTIONS OF PHENYLPROPIOLIG ACID BY RUPERT SAMUEL DANIELS THESIS FOR THE DEGKEPJ OF BACHELOR OF SCIENCE IN CHEMISTRY COLLEGE OF LIBEJiAL ARTS AND SCIENCES UNIVERSITY OF ILLINOIS 1922 Digitized by the Internet Archive in 2016 https://archive.org/details/additionreactionOOdani ) 922 X)22 UNIVERSITY OF ILLINOIS _ _ ^ . 25 . r J-2 2 Z 192 THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION BY iiy-n® r_t!_ aTiUPJl _ i§3-_s EN^tttfd S!he Addition React long of Phenylproplol j,c Ac1 rl. , IS APPROVED BY ME AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE DEGREE OF Instructor in Charge Approved : HEAD OF DEPARTMENT OF 5 0 jl ,rS*i 7'7^ f • ZIOVIUJI TO YTlfiSjVIWy \ 1 ■\ ',. ».v '■ IBl'* ■i . ■■ “ ~il - "I »- J . .V.'* ’ i ^. vtfr' r’. ^ ■i ■" v« - “ ■■ ■ ., ■.' i! ^ .Yfj ^i4 V^itv'i'Kh; ;jt &mx is;"'-' -.i - ^ - .4 **-— — -- ^ y*yf ‘--^1^ - « ■*•• - - . ' * «lf k^r'. ,J fpi ^:l ^.5>' ' V * > . i.u^. ,a 3ii< ‘*<> f^iUV' r-j ha ilK/fiTOT/Oftl^X^ K'J ^ • *iS’ -4f • * • ;<3ISK^* aa^slxsKi f* ■'If'i I . ■'. * “** rti ’ • " uT -xv ' '■ . ' - . ■ ■• u-<" ' . ^ - * •* • - V I. TABLE OF COITTEITTS Introduction and Historical Page 1 II. Theoretical 5 III. Experimental 8 A. Preparation of Phenylpropiolic Acid, 8 B. Preparation of the Ethyl Ester of Phenyl propiolic Acid. 16 IT. Summary 18 Y. Bibliography 19 - 1 - IITTP.ODUCTIO:^ AKD HISTORICAL Phen^?’lpropiolio acid has been known for more than fifty years. It has been a suoject of interest due to its great re- activity. next to orthonitrophenylpropiolic acid, it has been the most investigated of the acetylenic acids, orthonitophen^ro- piolic acid being used at one time in the synthesis of indigo. The unsaturat ed nature of phenylpropiolic acid, makes it very un- staole, so its preparation xs not an easy Ane, The grouping — C3C— 0 0 is unstable, like - C - CEg C - OH. Phenyl propiolic acid and its esters have been used prin- cipally in condensation reactions. It condenses with itself to form naphthalene compounds.^ The esters condense with diketones and substituted diketones, to form pyrones^, they condense with hydroxylamine to fono isoxazolines^, and they form addition com- pounds with malonic and scetoacetic esters, Glaser , first prepared phenylpropiolic acid by passing carbon dioxide into an alcoholic solution of 3—bromstyrol contain- ing a little sodium. The acid was recrystallized from ?;ater or sulphuric acid. 0 CeHgCHiCEBr - 2Ha - OOg C^IgOrC-C-OHa - HaBr - Hg He also prepared it by using phenylacetylene in place of B-bromstyrol. 0 ^C^E^OSCE - 2Ha - 2C0g 2C6K5C5C-C-0Ha Ehrlenmeyer^ used B-chlorstyrol in place of B-bromstyrol used by Glaser. A comparison of yields was not possible. Barisch® prepared phenylpropiolic acid by treating a-brom- cinnamic acid with the theoretical amount of alcoholic potash. He also prepared it by treating 3-bromcinnamic acid for a longer per- ■■ » '.■ » V ii-»/ II ■.( 0 1 j - 2 - iod with alcoholic potash. In 1884 Perkin’^ made the first complete study of the pre- paration of phenylpropiolic acid. He used two principal methods. The first method was to hrominate cinnamic acid, and then to treat the dihromcinnamic acid with alcoholic potash. This process gave a-£. h- hromcinnamic acids (mono) , which were separated hy their ammoniium salts, the a-monhrom ammonium salt heing the less soluhle The h-acid was then converted into the a-acid hy heating just above its melting point, or by esterification, in which case, the ester of the a-acid was formed. The a-ester or acid was then treated with alcoholic potash, and phenylpropiolic acid was ob- tained. The yields by this method v;as better than by any of the preceding processes, already given. 0 0 CgEj,CH5CHC-0E - Pro --- CgEgOEPr-CEBr-C-OE 0 0 2C.EoCH3r-0E3r-C“0E - 2E0E — CgHpC-BrzC-lsC-OE: -2KPr - HoO 6 5 g ^ ^ 0 C.E.CErCBrC-OE — -fheat^ CcE^C3r=0H-C-0E Cgnj!?3r=CF-0-0H - rOE — OgEtCSC-O-OE + The second method used was a modification of the first. It consisted of forming the ethyl ester of cinnamic acid, brominating it, and finally tresting the dibrom cinnamic ester with the theo- retical amount of alcoholic potash. The phenylpropiolic acid was recrystallized ifttm water, and the yield was B0-86f^ of the theoretical. 0 0 CgEgCEzCHO-OH - Gj^HgOH -fECl gasj C .H5GE=GEC-0B255- EgO Cgfij^CEBrCHPrC-OCgEg - SHOE — ~ CgF.gCsCC-OE: - CHBr - SEgU - 0 0 *^2^£GE C^RgCEsCHC-OGgHfe- GeH5OrPrCEBrC-0C2E5 If an excess of alkali was uSed the follov/lng reactions took place: . . -L r 1 I i -3- p + FOH — »• CgHpCHC!! t 0 pr ^.EuCSCC-OX + 2E0II — ^ CeHsCrCEo-#: E 0 CO 3 /OE (CgEgCrCHg + HCl — ^ In 1891^ a change v;as made in the preceding method, an eX' cess of potash was used and the time of reaction reduced from 6-8 hours to 4 hours* The yield, based on the ethyl ester of diorom- cinnamic acid, were 90-96^' of the theoretical. Michael^ recommended the preparation of a mixture of a- and b- bromailo cinnamic acids, by the action of dilute a(iuaeouE alksvli (£•5 moles for each mole of acid^ , and subseQ.uent transformation of the mixture into the a-brom acid by heating for a moment just above its melting point. The a-brom acid was converted to phenyl- propiolic acid by heating for 4 hours in a water bath with ZOf. aquaeous potash solution. The yield was 85f^ of the theoretical. Sudborough and Thompson^® showed by experiments that the employment of aquaeous alkalis tended to form -bromcinnamine , especially if the temperature was not carefully regulated, also tha-; the transformation of the a-brom alio acid into the a-brom com- pound did not take place so readily as was stated by Michael. The following method v/as adopted by them: hioromocinnamic acid was shaken in the cold with alcoholic potash f£moles^, the alcohol was removed by evaporation, and the two a-brom acids wrere separated by the aid of their salts* The a-brom-allo acid was crystallized from a mixture of light petroleum and chloroform, and then trans- formed into phenylpropiolic acid by heating for two hours on a water bath with ZOfo aquaeous potash(£.b moles). The acid v/as crystallized from chloroform, and the yield was 68-70^ of the the- oretical. / • O It - 4 - Sudborough and jamesH prepared phenylpropiolic acid from the dichlorocinnamic acid on treatment with aquaeous potash at 100°C for eight hours. The yield was bOfj of the theoretical. The methyl ester of phenylpropiolic acid was prepared by Liehermann^^ by passing dry hydrogen chloride through a solution of phenylpropiolic acid dissolved in absolute methyl alcohol. The ethyl ester of the phenylpropiolic acid was prepared 13 by V7.H. Perkin by a method similar to that used for the methyl ester. - 5 - II. TEECEETICAL In consideration of the different methods of preparation of phenylpropiolio acid, it was decided that the Perkin method ap- peared to he the best. A detailed study was undertaken with the hope of perfecting the method of preparation and ultimately in- creasing the yield. According to Perkin, who used ether as a solvent, for bromin- ating ethyl cinnamate, the addition takes place instantly. K 0 W 7 ever it was found that the reaction proceeded much more slowly than he indicated. The formation of a lachrymafcor made the handling of the product disegreeable , so chloroform was substituted for the ether, and no lac^ijmetor was formed. A, slight disadvantage was that the chloroform did not evaporate as completely as the ether, but could be removed under diminished pressure. Perkin obtained the dibrom ester by spontaneous evaporation of the solvent. "Since the amount of ester was not accurately known, if the theoretical amount of bromine were added, the pro- duct was alw^s contaminated by it. So the ester was washed with a sodium bisulphite solution to remove the excess of bromine, and then washed with sodium carbonate solution to remove the acids. A.fter washing once with water and drying the solution with calcium chlo- ride, ethyldibromoinnamete was obtained in the foim of slightly yellow crystals by evaporation of the solvent. The effect on yields of the different concentrations of al- coholic potash was next studied. - Perkin stated that the theoreti- cal amount of potash was used, but did not give the quantity of alcohol in which it was dissolved. V/hen 95f! alcohol was used it was found that the quantity had little or no effect on the yield. . ■ ■ f \ ^ ^ ctTC f ♦ ■ . . ' ■ -i V / j . ■ j •.r.' 0 . . - 6 - The potassium hydroxide obtained from the storeroom varied in com- position so the approximate emount of this potash was dissolved in alcohol, and then See of this solution was titrated with stan- dard acid,ECl. Sy this method the theoretical amount of alcoholic potash was added to the dibromester. The yield of phenylpropiolic acid was no better ‘ when the theoretical amount was added than when the approximately correct amount was used. The effect of an excess of potash on the dibrom ester was then studied. Increased yields were obtained when an excess of potash was used and the time of reaction shortened to 4 hours. The best results were gotten when one and one half times the the- oretical amount of potash was used. TThen twice the amount was added e large quantity of phenyl acetylene was produced. Uhen the alcohol was distilled from the potassium bromide and phenylpropiolate , there was some decomposition of the latter, near the end of the distillation. This was prevented by filtering- off the precipitated salts, neutralizing the solution with hydro- chloric acid, and then distilling off the aJ.cohol. Perkin dissolved the potassium salts in water, and acidified this solution with dilute sulphuric acid, precipiating the phenyl- propiolic acid as an oil, which solidified onns tending. The crude acid was then filtered, washed with water, dissoved in sodium carbonate solution, this was gently heated with animal charcoal, filtered, and acidified with dilute sulphuric acid. f?everel changes were made in this proce dure. After dissolving the salts ina water the solution was extracted with ether to remove any phenylacetylene and brornhydrocarbons v/hich might be present. The ' solutionnwas then heated with animal charcoal, filtered, and wo ■ ::> u. ,vr,t ' ■ ■ u .-■■■ ■ j . , . . / . ‘J* Q -» • 'f* : r: ‘ ‘ * 1 . . 1! - r-.' l> ’- ’uV r?^-, < *' .'il )C‘* ^ ■ ■ vv; _ SI . 'io "" ■ :': ■ 'r\ , "■( 1 * , ■ '. J r . "»■ •■■.■■'lOi.r , : iL 1 s. r; ' ' ' « ■ ' ■ : : aYi * )' ■^V , / ' / .i ‘ . ' ■K ■. ,//' tJiCiO :v .'‘Mr., ^ t '■' '*■' o.l\ ' ! '.A'-.n '..r '■, V J’fwoir ‘ jr ■:■ .’'t, '' ’ ■;.:l’' > ' .f » r • ^ "■ ■ ’ J il*- ;.' . ;., :;y n ■ <* 1 \ I I V : •-, i}^-‘ r : • ■ -i. ...., -,r, - ^ . -' 'v f., y.:.' ‘ , ■ ' ■S ' . i I'o X ifejjjiij \’ ,' v* .. ■ .. I,'-: r I T '■•Ti* . : f ; ;■ £ ‘I : ' i ,j; / j • • f. ; 'Xr- ■ It/ vij’O'.-'XT •:') r ■ 1 i.'.,:^ :■'. Jv.£ ;-.v V'" uc,!:- . . '0 J! i ' ■ .-f ; , ..u iiii/.f . T .1 ; / i: i iTx 5/ ■>.!■-.>• . V., - 7 - aoidified with dilutfe hj^^drochloriG soid. It was found that the charcoal had little or no effect on the quality of the product ob- tained, and its use might he omitted from'*1;he ahovd proceedute. I ' ’■ ' • ' k •<» y' ,.t'' ,- •• _ '.'J4 ■ , 1 -. ■ ■'‘r I* ^ .yt;6'r « Otf ^ 'J 4 # CJ -4i ,1 kW /4«JUJkf ^ ,‘^jj ^ ^ A *? J. t?*© i1 '■ ^ ' ^ ' -T-^ * ■' - r, ' j '•■jrmiD r. ‘ \ :■ ' 'Vk*;w ' I w './I !■ ai^^ mu i * f/' ;t. v^.v ''i ■■ '' 'V ‘ . S,Si ■ '■:* ' -7 ’ ?■ iW • • ■' i' '•%. ■'■ . >'V , - \ ' t i’ ' VT> ,, r ■ ii‘ „ ■■ v,' .,,■« ' • ^ AV,;i?(l|j^^ J ,» \ ' r': .,■>,. .-’Sipfiser' ■’ 7 I ‘ * 't . . . fife' ^ A B - af. : y,^- ^ #fe. * ' • ' IW' • ‘a •v'vrwff'-'j * , i 1 - ■ ■■; / G ; 1 ( . ■' ■ ri ; *; Otlo; Jt r^i.G. > .* 1' ■ 0 C f/ ' • .».■ i >0 ■■ •' T> ,:i; •; r'l' '..I'w! O.L :; -J : ‘ : j ' . - "yC' I •■ ; r.t, ' " " r •; -V ■-•.■ i.'C' - t. » \ \ ■ *,...0'^^ : :•• • '1 ll' • >• 1 . ,1 ) •vti-'. y: "0 '.'•J >'r. •/ Su ■.' 0^;- ; ^ ‘ ■■■ : . i: n ^ , . C"' > . ■' -,.'l ; iJfVJ -lO; • • ■ ‘ , -I- : 'k * -• '-0 'C { »i_T| ', y. ~ ' ■ , : ’ . ■ * ‘ u ' '’if - . t ol - :.'.o '.' l;c • . y r;) ^ f ;• ■ ^ I i^ry,'),/ o,:”' ro Vi (l:^ LurS' t , 'vr', j - •* ^ *■ ■ 'I i"f ’ •' i;^i c V- '■ ' ■ -j ir. .6%- )ii . ' . •• t-v-.-c >y ii;s ■ la OT oiyt ..J’JF«'^:^ • • oiliV ■' .Ijii; , w, '■ Ua.Q’ 9yi ’ ■ <•71 ■V .-foi , 4 '*> . • . ■■' 0*).^ ■ , r .^-.rrC‘; :y,_. ic -.Sm 'vr.vx^*. 07 c^' • , TuVO ii'a .•' 1 .‘iM • ;..i vr'Ji^r-'ci 'ic •/■vr' ; , ;■ . ;. * ' • • -1 • 0 -J/ •'•'•-'f. : ■ -i-i.-'*" o.‘ : •; ; ;• >t T: ,'(OM i-i- i.'-Ci'' •'•r j. n'b • iV I 1 5 •.6 C" 3 j i ' U ,'iC/ C • !•’•*- i ' '■-'• '•• lX«i ■'fiX'-.* : »■-• . ' OtU-- . / ■ . ... 11 •■’ . i ]-.r V c ■ ' '■ ';.i. »Vi i J. "OJI r V.;’vv' !' ■ * • r-=-r ,/: . ' ui; {. i -•'“T 5.' , , , ' ‘ . *JI* r.-i '/ii . ■ ;.-Lr* -• ' ' AA .. J* y. ' I r- ji - 9 - of alcoholic potash f 1 mol of ester requires 3 mols of potash)* The second portion was added to a trice normal solution. In each case the reaction was so energetic that the heat evolved was suf- ficient to cause the alcohol to boil. As soon as the ester had been added, each portion was heated to boiling for six hours in a fiask connected with an inverted condenser. The alcohol was then distilled off, and the residue, which consisted of a mixture of potassium bromide and the potassium salt of phenylpropiolic acid, were dissolved in water, and the solutions filtered. The solutions were acidified with an excess of dilute sulphuric acid which precipitated phenylpropiolic acid as an oil that solidified on standing. In each case, the crude acid was filtered off, washed well with water, dissolved in sodium carbonate soiLution, and gently heated for one half hour on the water bath, agitating well from time to time. After filtering off the charcoal, almost colorless solutions ofthe sodium salt were obtained, which on acidifying with dilute sulphuric acid precipitated the phenyl propiolic acid. The acid was then recrystallized from water. The yield, from both e±periments, of phenylpropiolic acid was very poor, and a 3eilstein test shov/ed the presence of halogen. A melting point of the acid proved conclusively that there was pre- sent some raonobrooinnamic acid. The acid obtained when a twice normal solution of alcoholic potash vrae used, v;ae the more pure. When the acid was recrystallized from water a residue remained which was probably phenylacetylene. Experiment §2 The same general proceec^ure was followed as in the pre- ceeding experiment. js &Ar^iri aai nJc. ^ ■’ Ti'i ■' 1 . f. «.' •> ': V • f • • ■ '' ; ' 'V J- ' td .r-o,r r ' .f.-; ’ '■ .’ ( ■:: j." : '' C'l; ' ■■ . 'U O'.'iT • • iCO ■■ ^ :• "in’" . I '''''.• o •::> ■' ■•■ 0 ^,i, .';■■■ >-^r. M '\ ^ tj . ■ ! i i . C JO’.i ' .■'* V? v^“ Ji - ■ oil' -l-.i ■ >■ jf - • , .:.j.‘.'i »i 0 ' *■ j ^ ii i . ’ C V i’.j -f V I I j :.' f ' . ■* ! 0 c: ■■ ■ j uic ’ f* > r i '’.te <> 1 : c ; Tia... , 'i>' \hs\9 K .' ^ I , *V/,' * , io-:* 1 I ) ( i ■ t r;l'^ .r-. : I V >>v» i . r sT T*«t : u* f *).' X 0 •■' ' • '■ ■• A ,y ;•'•< •: , »'oX-:. ' V I n'_* : _1 J' j ' ^ 7 w. ilUX*l;< 3 C , ■ : i; v: re- ' '•r o o ^ ‘ ■■■11' , J .<•-,■• V-.., ■ ' . . /' “I ) I' i; '\ I V* »'i'- ■ 'j < ''.' ? • ■■ n: b.t . * •( . ( : . f- V- ■ . '-■ : ' T^'. ' ■.*•.. -f ;l ••/■■:;/ ut:^) 'ir'vci'c;' • ■>;,' ' 1 -Mfi ■,v ' . ' 'ii .'• ‘sT ' ro l\kX . ' \V! ' .t r w/i r , .;aoX'^"-V r> 7 ' i';|, aji-' ,,£txv ' f, t> »'f . . (,. Y'X^Ci'‘£>T ":c. ' .'■ ■ . ■ ^^■ ';.•. ' , •;i" -.-"tc 'j rt't V » , ■' .■'»•; ““OY 'J • O.iV •:■ ■■ ■ i !>:■ ''ooX' ■ '*.n nt j. ci ' f“ 'iCi: >♦.‘•>,1 fijfri’t •'.■: •,•? 4|J 't-y.K'' C7' I t r * 1 t \ ■• CvgO'C''!.!! ti : : .V .; V • "i-dlT ■ X 10 I ‘ ' -tX '’i' . < •> '■■ ■ ^ 1 fii- ■ 7 i. 'V 0 .*? .' ’* J y ,* 7 .*>/-x« '‘T >ni 7 ’ 7 C.' ■ . : !■ B waw ga Lii.w. - 10 - 48 grams of oinnamic acid were dissolved in lOOcc of absolute al- cohol and hydrogen chloride jjassed into the soltition. The ester was separated and 18cc of bromine added. 97.6 grams of the di- bromo ester were obtained, which was an 89, bf yield, based on the cinnamic acid taken. 53.8 grams of potassium hydroxide were dissolved in 486cc of 95^ alcohol f approx. 2H solution), and the dibrom ester was added to this solution. The reaction mixture was refluxed for several days, samples being taken out each day. All the samples shov/ed the presence of halogen. 28.5 grams of crude phenylpro- piolic acid were obtained. I'ost of this was used in trying out various methods of crystallization, so no data was obtained as to the amount of pure phenylpropiolic acid formed. The potassium hydroxide obtained from the storeroom varied in composition from time to time so that it was thought advisable to find out just what effect this had in the results. In the next experiment the potassium hydroxide was dissolved in 9Uf alcohol and then 5cc of this titrc.ted with standardized hydrochloric acid to determine the normality of the soli:>.tion. In this way the theoretical emount of potash could be added. Experiment #3 49 grams of cinnamic acid w-ere dissolved in 100 cc of ab- solute alcohol, and the ester separated. 16 cc of bromine were added to the ester. A slight modification was made in the method of Perkin in that chloroform was used as a brominating medium in place of ether, because ether formed a l-a.chi3m.ato:f, (probably BrCH 2 CH 20 CE 2 CE 2 S^ CH 2 BrCE 0 from the alcohol .present ) . S* ■ I . ,'(ii .i . .'..iJ ' p -'. ‘r-v - . i'l '-L • liV, /. ,. ... ■, 1*'.^ ' o' .f .. . .' ■ .■ ..» . J ■ . 'f ’ ' .'■>.' -1 -V pi , fr:, : 'll . , , ; . • O'fiJ ; .' y£:|r'/«n o “‘j’ ' . c •I| J -V _ <., .. r . ~ < 'O A '•■ >■•: .^s « . ' - t ^ ; , .. ■. i' ^ ^ cli ■ )' 1 • - ■ r( '■ > ' A- yiox ■ )X •>:.X - / ■;r: ...'•. '■ '■ 1 ':■ . ■ ii’ 4' r , . . 1* - ‘- ■ ^ i . .1 V ■ J , . . 4 . . , s ■ .: D f, . ■ , ‘ .j ■ i * * i ‘X'"' ';;i .< ! 4 '■.).frr --r .V 7 • “ . ■* ♦ * -t .‘ .* . : 4 ^ , Ji ' ‘ • k • c< . ' ' J ■•■ o». rO>. ■ V: .. . r ■ '■ .j vsV^■ t . ‘ 7 ';' ^ :•.:• ii;‘ - V Vi be..' X€»;lft« ' , ."'j >W ' ' lo cr/iX ‘'ti Tw I ;■ ■ , ■ ‘ ' 7 - ’ * ,: ,' oji-ti:' \ .i t-'J . v' . < to 7 ^--;, . v.;c': . ■ ‘Ic •;• • . ■ ■ -yj c/i '■ f'.'* •-' ' ''.V^' i ^ . X' ' ■’;■■:* . 'JB'ti’Y I’" , ::.:v: ^ p • • Ir' I (*. ^ ’ V^l fi' . • ■ “ ■ i '.. xw.'i.Cr ■•- 53r;d;i;'..v X .:• . *> • u f ; . ; ,••? (t:i /' ' I ■'■ ■ ■''. ■ '-viL ' ''9 • i ^T(, •'•: ■ -yij ' •(- ■ t'./O ■ T # i {■.; >cf ■/’; . J .‘■'i'aC Vi- 't- :*~fi;:r.riT>c \, tfT i . 1 • pV •» Cii. -'■ X •• '- »» i ^ ' .» i • ' . ^' -n •./ >«» c'.l j ' icX . -V v,if ' ' t ■ I .* j • ,/■ A A"' ■ ■ ••■* K'r.: \ i;, *^'Ur •':.'c'"tf‘'f:.QX,io j.'i "o .'©-s,.'- Cf 5 .' , ■ *> ‘if '(tXV X;' : X'Tr ^ '•[.' •;/; • , ' iX _ ,1 11 - After 'bromination the dibrom ester solution was treated with a dilute solution of sodium bisulphite until the solution was a pale yellow. The acids formed were neutralized with sodium carbonate, the aquc-eous solution separated, and the last traces of sodiuip carbonate were removed from the dibrom ester solution by washing repeatedly with water. The solution was dried and the chloroform allowed to evaporate. The dibrom ester was crystallized in white crystals. 87 grams of the dibrom ester were formed which was 78f^ of a theoretical yield. Experiment f3a 20 grams of the dibrom ester were treated with 90cc of 1.3IT solution of alcoholic potash, and the solution refluxed gently for six days. Another change in the Perkin method was made l.ere. Just before adding acid to the potassium pheny3.propiolat e , the solution was extracted with three 50cc portions of ether. The solution was then boiled to remove any ether that might remain in it. In this manner any unchanged ester, phenyl acetylene, bromhydrocarbons , or acetophenone, that might have been present, were removed. The phenylppopiolio acid was precipitated v;ith dilute hydrochloric acid instead of dilute sulphuric acid. About 10 grams of the crude acid were obtained. There was e small amount of oil which was insoluble in water, which was probably phenyl acetylene. Experiment #3b 20 grams of the dibrom ester were added to 90 cc of 1.3H alcoholic potash, and the solution refluxed for 30 hours. After extracting with ether as in the proceeding experiment, the solu- tion was boiled with charcoal for about 30 minuted. The charcoal v/as then filtered off, and the phenylpropiolic acid precipitated. • n r 1 5 . y \ f i'.(.' .M “-i ••>('■ ,^ ,! . ' L' • H'li; ■ ,t ,M :• . H) • ; i. iO.' 1 1 ' ■ . t - s ■• U-'i '•f i.. O’.*.'- • :,:c<) .r,'« t..;’ !• r, ^ ^ g^fk * tjQ-^ «> ,'.r. : l. V i' '■ <» c c ■ . •i-"r . V ' ':K .' s 'm "■ ‘ la ' n ^ . to ^■/ 1-; (■ ’ !•>'■ - 11 . I '»v,' :■, r. f : ■>’• [i . L'l ' i. ' 1 1 1 / f " 'll . .f J -r^xo ^ :.’.V t*'iX ‘ j; ■ vci'ti*x'h ' liJl r.eirl'J' ■ . ' I*. ' ' , ■ ' 3 (r.;: 4 o; . . .. ^v■»rrai^^J V .' /.V -L/'. 1 r-.-^o©f- TO C. I '.J.i'tj^.. , li i.'*J ., ' J jJ .1, > ,. 0 /,' ' . vv ■’ rta^<'y ' /i’lAui ..I. ' ..Yh ' > 0 I 'iii.i '. X.:,TU r J ,r .ii.i . ir' I TH'/ •I • iOM-- ' ; n :;’.r.\ .).rr 'Y ’ i ‘I - 'So 'f-jrli* - v' j*. /y %/ * *^ *. * ^ ^ ' ■ iJt i_^ J .. W. i-‘. I , ^•-.■r T- ,'. 1*1 ,-. •*- li , Vi \i ! vr 'i;.. - 12 - The crude acid was then recry stallized from v;ater. 3,8 grains of the pure acid were obtained. Experiment #3c The same amounts of dibromester and alcoholic potash were used as in experiment -,f3b. The mixture was refl'oxed for five days. 11.0 grams of the crude acid were obtained and 5.4 grams of the purified acid. This was 62.2 of the theoretical yield. Experiment #4. 200 grams of cinnamic acid were dissolved in 300 cc of absolute ethyl alcohol, and hydrogen chloride passed into the so- lution. The ester was separated as in experiment #3. 80cc of bromine were added to the ester solution, and 359 grams of the di~ brom ester were obtained. This was an QOfj yield based on the cin- namic acid used. Experiment #4a 25 grams of the dibrom ester were added to 125 cc of alcohol containing 25 grams of potash. The reaction mixture was refluxed for four and one half hours. The proceedure was carried out the same as in experiment#3b up to the point of recrystallization. 10.5 grams of crude pheniT-lpropiolic acid v;ere obtained, and dis- solved in a warm solution of ZOf? acetic acid, as the solution cooled, it was diluted, and just at the point before the phenyl- propiolic acid came out as an oil, a few crystals of the acid were added. Phen^rl propiolic asid separated in perfect needle-like crystals. 3.6 grams of the pure acid were obtained. Experiment #4b 100 gra.ms of the dibrom ester were added to 500 cc of al- coholic potash which contained 100 grams of dissoivaBd potash. ■ r ^ '’ .o‘ ’• i X :; :>c^fn"00S- -^^'jiiyjTTlIlfi II 717 W • V ■ , ' ' ' ‘ ' “^>.W i1:. /Cl ; ; 1^' ./’ j, f 1 'rj *r/. ’ ■ ' ' 1 * 1* . , ■ »■ ,/..,y '‘T. j';;!.''': • • \ -C.4X: * l-X ) n i i ' • :'o •■ ■ fi : . •/■-; i ::0 .. V . : -.. « . k/ : . ■ -£., .•! '• / H' >1 t V. ■ -. - ’ V* *'• . '• ■ L . i ; ■■'•;.■ . ' : ,: ■ . .;,, 3 J ..' S • ‘s C- ; , . *' ' t;i_ , ' • ■•■''•ct ' .... ' . / i/J /JS U' oi4c/x- s ‘ . ....' i/f [.C • . f., • 1 fee' -V. ... . .'y -i ’ ii. f' . j ’ , ■ . » *J \i . 7 ' .’ J .. .... . ./ ■ - . ;?!. ;i!Mn ,.t: -5 4 ,. i' iiicc ■ .-i'. •v. ♦ *• ; ■ L' C n! ' . ' C -i ' . ■ t 1 _l, - • «'■ 1 ■>'■ l;;Oi .t ’> . I 1 ■i X' xow tivi , ,.r,_. ->. 4 . -!ur. ..v ' -r » f ..> J-.V ' ' I ■ vXc/t). '•.vioc*. .'.ii :'>e':s^-e . c ' . • ■ ' . ; ' >< '• ■ ' > ' •X- •>ii-.ri • ;«■! -iSri ^ V'- .; f - ' ■ 'f ..Vi> to J 1 ISI& M-!; ,r: h m -» ■■ M : f vf ,0 •.. ■• ^C:C ■^^. c I ■ j oi ti; ■• ;o'’ The reaction mixture was refluxed for five houre. The procedure was carried ou the same as in experiment #4a. 21.5 grams of pure phenylpropiolic acid were obtained. This was about a 50f theoreti- cal yield. Fxperiment #4c The same quantities of material were used as in experiment number 4b, and all of the conditions were kept the seme. 22 grams of pure phenylpropiolic acid were obtained. This was of the theoretical yield, Experiment 140 grams of cinnamic acid were adcled to 170cc of absolute ethyl alcohol. The same procedure v/as carried out as in experi- ment #2. 53cc of bromine were added to the ethyl ester and 242 grams of the dibrom ester were obtained. This was a yield of the theoretical, Fxperiment #5a The same amounts of material were usee, as in experiment ^4b, The reaction mixture was refluxed for five hours, and apparently all the phenylpropiolic acid decomposed into phen^?'la.oetylene . Fxperiment #5b The same amounts of material were used as in experiment #4b. The reaction mixture refluxed for three and one quatter hours. After the alcohol was all evaporated off not all the solids dis- solved in water. The part that did not dissolve ?;as filtered off. After the aquae oue solution had been treated with charcoal, it was acidified and allowed to stand for two days. On filtering an oily substance , which was probably phenylacetylene , went through the filter paper. 15 grams of pure phenylpropiolic acid were obtained. .‘“It Lt" 0 ’v. o/ltE ;.L*C Kf.;-' ■ ,.i-‘ . jifk 0 ^;-; .'^j.r.t J ."r i- i f ■'%^lX',flt V .fioo •’‘ r ' i li ‘j, ' ■ -♦'•* . •'.;, ^ j , -A^.-,,: ■ "* ' '“-r *- I . * “^ * ’“ ■ ' ' •"> 'i ■)1« :.* .);“.ci.' )v " J. '. f.'„ ' Xlij^ i¥ '.f ^i?*!** . :: : V ’ti ••■ '• ,/' Wi /-■ y it-ni .t:;-; ’/ i 'Ti-v » ■ V ■ '' ’ 'OCT-*; .flit .u . . # 4 , t jj ■ ' I'-f i ' , r -'r. V. V w» ■ , ‘ i. .: f * ^ ■ ' ,. • ■ /•>v.“ •. ; • •. < • ■: 'iU- i ' ■. ‘ ^ M*: .; '.' u ■ y T ./ " "!;a', rr>:: kV:'. ' >• h'. »4 - ,• . f r» it ; /•“>-t)'<. C v‘-> :. . 3 ; *'. .‘, 't i'X« /- . • •t'^ ; t .'A- T“'.' o.-,- i' . . ' rf^> 1 ■ ;v - “ -*■. ■ t'iC 1 •./( X .. -..:jr;, : '. 0 , ,r-c , or , \ y A O w - »;j’c.':.Crv ':. (7 f I -,.■ • >:^or; ett ' .’ ' ■ " ' ':'' '. ^ ,„c,''>' ^ “' '■■ ' .'■ .' I }r.tp :^r ,r,v ' j ‘ ■ . * ' ■ ;*' ■’■ ' ; . \ . I ,* . ' . 0*' c .j; ' * \5 '•■ • '•■ Uxuic'. •' ^ : a:- >: « ^ n'i'C : >!L?rf .-. ',C'-^.,i.J! i. . ■'■ ,<-:■" L iy* t. ' ». o; :. 1: T;-;! V- '■ • * - ■r ■— ? g"r ' ' - ' ^ " ^^“^•r-- J^ ‘‘J r ' r f- t. ...\ fti" ' '.rmiiv'. -14- Experiment tJ=6 £93 grams 0 (f oinnamio acid were added to 4£5 cc of ab- solute ethyl alcohol, and the proeedure carried out the same as in experiment §3, 114 oc of bromine were added to the ester, and 638 grams of the dibrom ester obtained. This was of the the- oretical yield Experiment ;f6a 100 grams of the dibrom ester v;ere added to 5C0 cc of alco- hol in which 75 grams of potash v/ere dissolved. The reaction mix- ture was allowed to reflux for four hours. The procedure was car- ried out the same as in experiment ;f4a. 41 grams of crude phenyl propiolic acid were obtained, and from this amount 18 grams of the pufe acid. Experiment f-6h ZOO grams of the dibrom ester were added to 880 cc of alco- hol in v;hich 175 grams of potash were dissolved. The reaction mix- ture was refluxed for four and one quarter hours. The procedure was carried out the same as in experiment #4a. 1.11 the phenjl- propiolic acid decomposed into phenylacetylene. Experiment #6c 100 grams of the dibrom ester were added to 30C cc of abso- lute alcohol in which 60 grams of potash were dissolved. The rec.6- tion mixture was refluxed for six hours. The procedure was carried out the same as in experiment #4a. 16 grams of pure phenylpropio- lic acid were obtained. Experiment ^6d £00 grams of the dibrom ester were added- to 600 cc of alco- hol in v/hich 150 grams of potash were dissolved. The reaction r-TTT^ Y . W- ■ S ?- ’• ;’. - S^’v ufti ' tvi '. Iv /* ,i;<. :..' ....'* otv£;,j ', -ji r. ' '}d ;.•.(' ■• . .' -J .V*: w ' ■ r + ■-.. “ - ,, : coS ^ " .1 < .*: 1 > ;•: f:iC - rrc .X'O^rTyi ’' ^ . _ <.-’i;!^'V ^ -- f;,‘0' "e nt> ■»'’JC/ • * -U . V . 0 '; lfJt 0 ''J j » . J ;c '*, . '-’ l ;.!:.: ,.C ■:■ : ft . iC ’ C '*-! V - r ' U . i . 0 . ^ X J ■' vJ I r .; ’-0 (.'**■ '’ ui . ■’' .' o"::j ' ' X '>. \ i.i.. .‘, - t' - :.'r CvT ' '’ ' ■’ «>».'.' '*'.’ L ' :o ..-.A i.'C. . u , f -' ie i -.^£iti ■: I v .:.::.^ x . ■ .l\*i.OC' !' -.i I, ; 4 . r . I ,■16-. . / *' • ';C'>.'. ',. ..c-i X') ' K •" ' a .: t' V' . 1. i Ic \ i ' „ / ':' ojr- ► •» r- • .. ’ 'rni.-v • .- ■• -■ ,:r,f* ut ':"* -' ' . .j .. * yur - ♦■,-< ’-s ,): , t-ti:!: -)Xa <-u. >v’ t » 01 j / ' V ■■ J-\^ ■ ■■ T ■ ' '.*’ ’i'V* .. 'v • ■ .■Si f<-,; M i*’i' •' ■’.: :'j.‘. jr’f'i' ic ' - h** ' -0 ' ' ' " ‘ ! 1 ; ■ j . \ ,...:' ■:'". c;f '.••;•:•» .' '*»■•*;■•:•<• ; 0 '' X -- : '• .} i ^ '-<: B . • ■ ■■ ’..• .nlij ri'i .'•fr ■: ':■'' ■! "I ■ .* ' j , Jr - . .-ire : J ’. ‘ f - ".' j ). c .-1 I /■: t ,0 Of : ‘ r * •"’ c '■ ' ' >*c . .;' ■■ .c: r» 4 ^ . . ■: !. .' , . ,/,. r - .‘ ' J - ■'. -15- mixture refluxed for four hours. The procedure was carried out the same as in experiment #4a. 60.5 grams of the pure acid were obtain- ed. This is of the theoretical yield. Experiment #7 £98 grams of cinnamic acid were added to 450cc of absolute alcohol. The procedure was carried out the same as in experiment number S. 117 cc of bromine were added to tl^e ester, and 547 grams of the dibrom ester were obtained. This was 80fj of the tlie- oretical yield. Experiment #7a 200 grams of the dibrom ester were added to 600 cc of alco- hol in which 150 grams of potash were dissolved and the reaction mixture was refluxed for five and one quarter hours. The procedure carried out was the same as in experiment #5b up to the point of recrystallization. The crude acid was recrystallized from carbon tetrachloride. Pure white crystals were formed which did not con- tain any halogen. 21.5 grams of the pure acid v/ere obtained. Experiment #7b 100 grams of the dibrom ester were added to 300 cc of alcohol in which 75 grams of potash v;ere dissolved, and the reaction mix- ture refluxed for five hours. The procedure was the same as in ex- periment #3b, up to the point v;here the alcohol was distilled off. At this ppint the potassium salts were filtered off, and hydrochlor- ic acid added to the solution until almost neutral, and then the alcohol was distilled off a This eliminated possibility of decom- position by potash at this point. The rest of the procedure was carried out as before. 26.7 grams of pure phenylpropiolio acid were obtained. This is 86.5 ^j of the theoretical yield. - '*^'• ■» “ isdAa .,. -i • t;.-. .•&C'*J , . • '.; : •'/-;■ <••■* ftr-V •• j ;:Tfl .:I!j - li ^'■ -i ixa 9 CUT . W- 't'v ' -v# -i ' If ^i«i, |f -T 4 ) j: ■/ J,'k : i ■:::. •' t i's‘ “■■ y wi.i. i 3 ". f » • Ji. i ? ' , 1 . i’ ! ^ hIV ’CI^-IS ''L'l'i'irt'C ■:.+■ '/r. -i. ft;- V.' .. r> . :r 'o ),.' . A . - -.J ,'Ji i JvT' ^*T ■ •' i I. Ill tl i ,'' "l . C ■'(*,' f ,1 M • • I 1 '.T, r*:vii‘vxO {• ■ % fS' .• ?•♦ - 'J Oit 1 _;c 'f I ,- ■•\- r.c J. j't ;<^)’i ./•'V...C / . i He.: .u i- ' '■■ rc'Mooi , : '■ :*‘.r.; . .'•r.O i-r,i 'V' i • ■ j I ;> <(■-. ,-■ . f a..:; i'rv : ' ■' ; I I , :•■ , % - .-J • ...•.•; ‘ . J yi’R '. I Vi ■ o virr v «•.; • i. iv ‘7’' : i ‘ '• '/ J '’T i' ' J. J ’ .' ■ ■.■' ' i ' ^,'.1 i .'■f, . I - • •/ J.' : ) . .c'ti'. t'i i,/ ■ » ' L..X » V- . \ r: .0 . . I'T ■ i.. ‘‘ , ■ ' ' * 'V ' ' ; •; . ot, ‘ f ' ' . '.' \Jt. 'iM '-’v' .-'• ■‘'’'Tc r i • t- t ■ . :f . T‘'» '''. rf«i.c . .Vi ■ -y- ' ■' .■’1' /.l.fXi I,;.;,' ,,jrl ,. . ;■ :i{ , lyiiu - ‘L'O i' .V »» <• ( •wr:;' 'i. ‘■■iJ:; ' . ’ >*i'; '•? ,. ' >: J. .7 '.i'f.rj • .’ •- ':i'^ ♦ 7'.:' n'o ". ■;f;7 :, ; a'rr^.'fec' " 'y ’r-' ■• ■ t-,-. " ■• -< >' (' ■’ ' * •*" ‘ ■* t ,. . . , . . • • ■• - . Jl Ui.' .j-L.iqt ,v- \ ! r uu': .f inq pAiX‘,'f' I ■ . . . 'i •> Oj .0 i ‘ J 0. e i } ' .T.' i'li'-iC/J .-«. . V J' I ! L I . /. : (( t I* -16- 3» Preparation of the Pthyl Peter of ‘Phenylpropiolic Acid<> Experiment ^8 6.8 grams of phenyl propiolio aetd were added to 20cc of absolute ethyl alcohol, and dry hydrogen chloride was passed thro the solution until completely saturated, and then the solution was allowed to stand over night in a stoppered flask. It was pour- ed into 250cc of ice water and the ester separated out as an oil V7hich was separated from the aquaeous solution hy extraction with ether. The ether extract was washed vdth dilute sodium carbonate solution until the aquaeous layer was alkaline to litmus, and the excess sodium carbonate was removed by washing with water. The ether solution was dried over sodium sulphate, the ether evaporat- ed off, and the ester was distilled under dirainished pressure. At 21 mm of pressure the ester was distilled over at 160-163°0» About 5 grams of the ester were obtained. This is about 62. of the theoretical yield. Experiment #9 23 grams of phenylpropiolie acid were added to 25cc of absolute ethyl alcohol, and tho procedure carried out the same as in experiment #8. At 13 mm of pressure the ester distilled over at 153-157°0. About 15 grams of the ester were obtained. This was 55f^ of the theoretical yield. Experiment HlQ 74 grams of phenylpropiolie acid were added to 75cc of ab- solute ethyl alcohol in a 250 oc flask, and lOcc of concentrated sulphuric acid were added to the mixture. Another flask containin£ 200 cc of absolute aloohol was connected to the 25C cc flash, the connecting tube passed beneath the surface of the acid solu- -17- tion. A fractionating column r.ncl condenser was also attached to the £50 cc flask which was heated to 104-107°C. The absolute alcohol in the other flask v/as heated gently to its boiling point so that it took one hour end fifty minutes for the alcohol vapors to pass through the solution. The vapors absorbed all the water that was formed during the reaction, and the then diluted alcohol 41 was constantly being fractionated off and collected at the dnd of the condenser. 3y this method the reaction was continually being shifted tov/ard completion so that it did not come to the same equilibrium. The ester mixture was poured into ice and water and the rest of the prodedute carried out the same as in experiment #8. The ester v;as distilled under 12mm ijressure at 153-155°C. 8C grams of the pure ester were obtained, which was 9lf of the theoretical yield* -16- TV Tne experiments on the preparation of phenylpropiolic aoid led to the following conclusions: 1. The substitution of chloroform for ether as a hrominat- ing medium was an improvement over the method of Perkin since the formation of lachrymating substances v/as avoided. 2. Eemovsl of excess bromine by means of sodium bisulphite solution gave a purer product. 3. The concentration of the alcoholic potash had little or no effect on the yields of phenylpropiolic acid. 4. The best yield were obtained when one and one half times the theoretical amount of potash was added, and the time of reac- tion was five hours. 5. Decomposition of potassium phenylpropiolate was prevent- ed by filtering the precipitated salts from the alcoholic potash- solution, neutralizing the filtrate by means of hydrochloric acid, and distilling the alcohol from the neutral solution. 0. Oarbon tetrachloride was found to be the best solvent for the recrystallization of phenylpropiolic acid. The experiments in the preparation of the ethyl ester of phenyl propiolic acid led to the follovnng conclusions: 1. The best results were obtained by using sulphuric acid as a catalyst, and passing absolute alcohol vapors through the mix- ture of phenyl propiolic acid and absolute alcohol, maintaining the temperature near 100°C, so that the diluted alcohol vapors were continually distilled off. ^ o'.t * ii 'U’' . 1 .^! (- lL:ui I JJ .' . . r. • ■- (■ -'t 'yi T ui :trn > 1 . * ' ti, ’ ^3 v-l't ^■ 'V. > 'X’ ' r-:*' ' '■' ! .. y' "'ul. !.' . • V * ■ If ■ 'h'X 'f "7 ■ , '. '. ?A. . • ; • ' . '■ ';f' »:'.(/ " ‘ ■' ‘S’ •,!('. . ■' -vii'.'v : ft' A- *.••• t 0^- V' ii *V t • ' 6iu '■. ■ \i' } >1 J I'ljo. {}•■£ *»■ '■ wJ*!// - *T flU" 5 •?"••■ ■)Jr*i. r? oj ;<■ inih-f.;.' -L'J' ; ^ -19- y 3IBLI0GPJIHIY 1. J. Aia. cnem. Soc. (1910). 32, 212 2. J. Chem. Soc. (1884), 45, 415 S. J. Chem. Soc. (1908), 93, 431 3. Compt. Rend. (1907), 144, 1281-83 3* (C.A. (1907) , 1, 2597 4. Ann. (1870). 1^, 140 5. Ber. (1883). 152 6. J. Prakt. Chem. (1879). (2) 20. 180 7. J. Chem. Soc. (1884) , £5, 170 8. Ber. (1891). 24 , 4113 9. Ber. (1901), 3648 10. J. Chem. Soc. $1903), 83 , 680, 1154 11. Proc. Ckem. Soc. (1905). 67 12. Ber. (1891), 2589 13. J. Chem. Soc. (1884). 45. 174