INDUSTRIAL AND ENGINEERING CHEMISTRY
June 1948 =
01
refer5 to effect of friction at t h e tube XTalls
,8 = refers to effect of the thrust of the burned gaq y = refers t o effect of the buoyancy of the gah stream LITERATURE CITED
(1;
"Combustion," 3rd e d . . p. 110. T.;astun, h\lnr-k Printine Co.. 1932. (2) I b i d . , p. l i 7 . (3) - h i . G a s . L o r . Testing Lab. Bull. 10 (3Inwli 1940). (4) I h i d . , 17 (August 1943). (5) Ihid.,26 (May 1944). (6) Ihid.,37 (September 1045). ( 7 1 Berri-. JY. > I . , Brumhaugli, I. Y,, Moultoii. G .I:., a n d Siiawn. G . E . , .\-nfZ. Bur. Standards, Tech. PiLpcr 193 (September 1921). ( 8 ; F:wald. P. P., PSsclil, Th., atid Prandtl, L., "Plij-sic,>of Solids mid Fluids." 2nd cd., p. 251, London, Blacliie and Son, I9:W. (9) I h x . , p . 226. .hi.
Gas Ssaoc.. I~
1129
(10) I t i d . , p. 277. i, l l .) Komalke. 0. L.. nnd C'eaelske. X , 1 1 . . ..lni. Gua .4880c. /'roc.. 662-86 (1929). (12) Landolt-Bornstein, "Physikalisch-rhemische Tabellen," Pup. Yol. 1, p. 143; S u p . V&. 2, p. 137, Berlin, J. Springer. (13, Lewis, B., and von ],:]be, G., "Conihustioti, Flames a ~ l dExp10iioiii of Ga.;eh," 13. 203, C*aiiihridpe. (":itiibri(lgc T-iiivcrSity Press, 1988. I
.
(14)I h i d . , p. 342. (151 Lewis, B . , and von Elhe, (;,, J . Chem. Ph,gs., 11, i.5 (lCI1:3',
Properties and Uses of Alkanesulfonic Acids 1lie alliane~iilfotiicacitls ((:,'II:*~ - ,SO,II) ~ i u \ -beeti e Imowri for m a t i > > e a r s ; tbeir prrparation arid some of t h e properties of various nierrilmrs o f the series have been clescrilJd in t h e literature from time to time. . i n excellent re\iew o f prel-ioits work on the clieinistr>-of these acids is g i v e n I): Suter (8). -ilthoirgh a few of t h e alkanesulfonic acids of highrr nioleciilar weight ha\-e heen produced for s o m e t i t n r o n a coritniercial scale for t i w a e surface active
agents, allcauesulfonic acids of lower molecular weight have remained laboratory curiosities. Recetitl) this laboratory developed a catalytic process for large scale production of either individual or mixed alkanesulfonic acid*. This paper describes t h e preparation of the C to C, acids, summarizes published inforniation on their pli? sical and chemical properties, records new information conrernirip these properties. and siiggestb potential uses.
TH"
until the transform:ttion to sulfoiiic~:~i*ids is vir.tu:illy c o t u 1 j I ~ , t ~ ~ . Few side reactioii.r occur, a d yiclds of tc~hnic.:alsult'otiic acitls approaching the theoretical are obtsiiiccl. The process was applicd to the preparat,ion i l f nict1iaiic:- :tiid etlianesulfiinic acid$, b u t the chief eidphueis was 011 synthesizing a niixtui.c~of acids. Crude alkyl disulfidcs, averaging approximately two carbon atoms per alkyl group, and consisting chiefii. of symmetric:il mid unsymmetrical methyl, ethyl, and propyl disulfid(,s i n all possiblc combinations, viet'c oviclized to yii,lrl :L mixture of niet hane-, et harie-. propaw-. and prolmhl>- wm(' hnt R nesulfonic acids.
, 7
catalytic riictliod dewloped for the synthesis of these acids is relatively >iiiiple. By use of this process primary and -icinil:iry niercnptans, or the corre.3ponding :~Ikyldisulfides, have I , t x t i osiclizcd to all~anr~ulfonic acids of 90 t o loo('; strength. Tlii, i ~r-i.i.-:ill tjiluatioii* are :
sm1-r + 3 0 , +2~s0,1i 21j-S-S-R -+ 502 + 2EI2O +4IISOSH
m y SIC 4 L A N D CII E ~ I I C A L PHOPERTIES iti
t h c i liic
ixtiii~c~,
alkj-1 disulfides are eruploj-ed as the starting iiiaterials cnre is talien t o csclude water from the svstcm. alkanesulfonic ~ihvtlridescan lie obtsined. \\.lic,ii
Thc loiver all~tnesulfonicacids arc strong, nonoxidizing m%k. \\.it11 the ewcption of incthaucsrilfonic :tcid n-hich mc>lts at
~ i i d
:I
Laboratory oxidation of dinietlij.1 arid diethyl disulfides has ?-ielded products containing u p to 8OrC of the corresponding suli i Itiic aiih>-dride.s. The osidarion of alkyl disulfides t o alkaiiesulfotiic acids is now being csrried out successfully on a pilot plant xcnle, and it.. ti,ari;latiori to coniniercial scalt' is c>spwted in the 11c~arfuture. In the operation a mixture of thv aIl.lt l i d f i d e s a ~ i dthe :ippropii:tte aniciuiit C J ~Tv:itilr are o s i d i z i d i n tile pi
c 0 1'11 1 ( i l l I l l 1
B.P.
;c. ~~~
. 11111.
iJ.r', c'.
SI,.I ; I . .
2io/4O0 C'.
1.0 1 2 0 (1 1.4844 i n 17 0 1 3341 1 0 +7 i I 2516 13R 123" 1 0 -~1,5 2 I ii106 CHaCHrCH:CHrS03H 147 0 3 a Boiling points obtained in thl, laboratory. T h e value for C'I13CH!SOsH)C,Hz (synthesized i n this laboratory) is approuiinate, iince soinc decompo-ition occrlrred a t t h a t teriiperatlire a.nrl r ~ r e * ~ i r e .
CHsS03H CI13CHzSOIH
122" 123"
~ ~ $ : ~ ~ ~ o " , 2 ~ ~ ~ ~ I b
INDUSTRIAL AND ENGINEERING CHEMISTRY
1130
Ilexanc nietilvic!.i.iol,ellt~lil,
Benzene 'I'oiuene o-Clilorutului,nc 1-Hexadecene E t h y l di5ulfide '1
R a t i o of a r i d
0 !!T I .I O
0 OH
2C .(i 15.9
1 Y $1 8
>olrcnt
0 19 7:)
0 00 0.00
.> ,I35
Y 02 4 84
1 :O 0 88
l.i8 038 1.40
9 01
0 23
1
o
3.26
13.i
tn
o
iy
=
i ! j
ii
2.18 40 0 "1 4
..
L'.tiG 12,Ylj
0 0s) 9 62 3.91
7 58
0 71
A1i-c i l i l t >
..
o:in
1 TO
1 : 1.
:ire 20 C., t1ic.y aw oily liquids itt oi,diii:ii,J. t t ~ ~ i i p ~ iu~ :~i ts . TIIVJall quite high boiling and caririot be di>tillccl at atiiiosphrric pi'casure ivithout deconiposition. Sonic of them, hoiv been di,stilled unchanged under rcduced pressure'. l'iii.4c:ll properties (9)are shon-n in Table I. Typical conipositioii of tlic mixed alkanesuliunic :icicl pi'oducid o i l t h pilot plant ~c:ilr. I V I Y conipletely niiscible, eitlicr by simple solution or by
30.133
li,.. .
70
20
i0
3 .j
i0
1s
30
10
30
12
INDUSTRIAL AND ENGINEERING CHEMISTRY
June 1948
0 2;l 1 ,:I h G : l ci c,:l li 6 : l 1 '
b
60-70 Same Same Same 90-100
Boiling range 40-49' Boiling range 97-99'
l.i> 1.75 1.7; 2.60
12.0 l1..5 38 3 31.9
1.2.7
26.i
C.a t
i6.O 59 .I 65 9 39.2
1.1 11.1
4 0 1 2 1 3 1 1 3 0
.j ~ i i n i .
C. a t 3
inin.
Olefin. moles ,riiueAe, moles RSOaH, moles Reaction t e m p . , C Reaction t i m e , hr. \I-t, 7 yields (based o n olrfin! tut-Butyltolucne Triisobutylene Tetraisobutylene 0
8 0 1.g (I,,
1 2
4
0 0
70
1.3
after n-hicli the flask m s cooled rapidly, and the polynit'r layer ted, n-ashed a i t h ice wtter, and quiclily transferred to apparatus. T h e polymer was distilled ~ l o ~ vthrough ly ate Stedman column; occasioiial reduction of the pressure kept the boiling flask below 150' C. T h e data obtained when diisobutylene iy polymcrizecl t)y mixccl allianesulfoIiic acids under various contlitioris are givcn in Table cs the principal polymer fornictl !\-as teiraisobutylt of higher polymerizing temperature, lorigcr reaction time, and larger amount of acid is to increase the amount of trii;obut>-lene formed. These results indicated t h a t the fast reaction is the formation of tetramer, whereas the trimer is the result of a s l o depolymerization ~ of dimer to monomer, follo\recl hy copolymerization of monomer a n d dimer. POLYMERIZATION OF DIISOBUTYLENE. A 500-ml. three-neckccl flask, provided with standard t8aperjoints, was set u p with a st,irrcr, reflux condemer, and thermometer The flask was charged with 6.G mol: s of Eastman diisobutylene and 1 mole (120 grams) of 915, mixed (C, t o C,j) alkanesulfonic acid. The temperatwe of the contents n-as raised t o between 60" and 70" C. while the mixture wits vigorously stirred. After 1.75 hours the stirrer ~ Y V ~ L S shut off, the mixture transferred to a separatory funnel, and the. acid phase n-ithdraw-11. The polymer layer was washed sevcr:iI tinies xvith warm water, settled, dried by filtration, and fractioiiated at reduced pressure. ( I n later t,rials 100" C. \vas found to t x x a prefcrable polymerization temperature for general use. 1
34 66
..
.\\-?rage molecular vcigllt indicates triiiobutylene.
at the specified temperature by esteriial cooling. The polymer layer obtained vias separated, n-ashed free of acid, and fractionally distilled through a twenty-plate Stedman column. T h a t the three polymers obtained under these conditions were the simple dimer, trimer, and tetramer vias indicated b y the narrow boiling range of each. - i t 30 C. propylene is absorbed by the alkanesulfonic acids to foi ni the iaopropvl esters of the corresponding acids. 1-Butene and 2-hutenE bei;ave similarly. ISOPROPYL AIETH.iSESULFOS.kTE FROM P R O P T L E S E . The iS0I Y R ~held
froiii tlic storage tank and the gas vented. The bomb ivas conriectctl ngaiii r i t h the storage tank and allowxl t,o react for half an hour. h t the end of this time the tank pressure dropped; tlie storage tank n-as reehnrged again to 40 pounds per square inch,
-
1131
ding the venting, was repeated (tlie vent11th of inert gases such as air or propane). bomb xau removed and weighed. T h e the bomb had gxiiied a f e x g r a ~ n smore t,haii the theoretical glit,of propylciie. Tlic sliaker n-as then shut off, and the bomb as l.~olatetlfrom thc storage tank and alh,wxl to s t m d overliight under pressure. T h e product c o n s i s t d oi i ~ e a ~ ,the l y theoreticd ariiouiir of isopropyl nii~tharicsulfonate plus :I trace of sulfonic acid. If desirable it roultl be further puri-
ALKYLATION
hromatie hydrocarbons can be alkylated with isohutyl(1iio iyith alkanesulfonic acids as catalysts. Under the eonditioii.; used the reactioii was s l o ~because the competing reaction o f polymerization proceeds concurrently and at a greater rat(:. K h e n isobutylene was passcd into toluene at 70" C. in thc presence of mixed acids, the major reaction product was t1.iisobutylcne, even when the toluene was used in large molar excess. K h e n isobutylene was fmt polymerized by t,he mixed acids at :r similar temperature, and toluene added t o the resulting m i s t u d , no direct alkylation of the toluene b y the polymer occurred. T h e only alkylation product IYas fer!-butyltoluene, which probably was formed by react,ion of t h e toluene with monomeric isobutylene resulting from the depolymerizat,ion of the polymers. The combined depolymerization and alkylation reactions were verbs l o ~ as , shown by the fact t h a t the yield of the tert-butj-ltoluene n-as very low even after several hours reaction time. D a t a on thc alkylation of toluene bj- isobutylene arid it,? polymers are shon-ii in Table V. Plienol is alkylated readily by olefinic compounds under t'lit> influence of the allranesulfrinic acids. L-sirig a cat'alyst of mixcvl alltanesiilfonic acids (91% RSOJII 3 5 H2S0, 6% €LO), thc' major products obtained when phenol as r e x t e d viitli various olefin polymers wcre:
+
Olefin
Mole
Rem-
Ratio, Phenol: Olefin
tion Temp.,
C.
+
Yield a i Ilononlkylphenols,
5-
fietl.
The c,ffect of temperature on tlie reaction mixture of isopropyl and metliaiiesulfo~~ic acid \vas iiivestigatcd in a
1iic'r 1i:iiiesulfonate
The product distribution iiidicatcs that, in the case of tetraisobutylene, depolymerization to tliisobut,ylene occurs prior t o aikj-lation; with the propylene polymcr, tlirc,ct alkylation nithout depolymerization takes place. -~IXI-L.LTIOS
OF Pn1:soL.
.I 1-liter, three-necked tlaak wir I L
standard taper Soints ~ s t sfittrtl n-ith stirrer, thermometer, dropping funnel, and condenser. Tlirce niolcs of phenol were meltcd, and pourcd into the flask, arid 100 grams of alliaiiesulfonic acitl
( g l y G mixed) were added. The phenol and acid w r e stirred into one phase, and 1 mole of olefin (Cis polymer of propylene: was added through the dropping funnel. The temperature wat'. held at 45' C. -1fter reacting 2 hours, 300 nil. of water were added, and the temperature was raised to 90" C. The stirrer ~va:, then shut off, and the phenol mixture was removed, settled, a n d xashed again with hot water. Distillation of the alkylate gavc ;a yield of 7SoC pentadecylphenol.
1132
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 40, No. 6
id distilled at 50 nini. pressurcj. Yield of pure inethanechloride (b.p. 82" C. a t 30 mn1.J \vas 57r0 of theory based'uri sulfonic acid chargcd. Temp.,
C.
27 20 2: 25 29 20
27
20 20 20 20
501) , G./100 Cc. 1 1 ? 0
144 167 203 39 68 73 81 87 128 98
in4
ESTERIFICATION
T h e nonoxidizing characteristic. of the C A R B O X Y LACIDS. IC alkanesulfonic a d s make them particularly applicablc to the thsterification of carboxylic acids. There is less tendency t on.arti formation of objectionable color bodies than is the case \vlicii the conventional catalyst, sulfuric acid, is used. This general field of application was not studied intensively, but in the esterifications tried thus far, advantages were indicated. I n the esterificaatioii of olcic acid with ethanol, the color development during the r2action was much less when these acids were used as catalysts thaii \\.hen an equimolecular amount of 98% sulfuric was used. Iri the reaction of benzyl alcohol and acetic acid, the yield of estCi' was much higher with the alkanesulfonic acids than with sulfuric because less resinous mat.eria1 vias formed from the side reactioti of benzyl alcohol condensation. It appears likely that furthi,r, investigation will reveal many other esterification reactions i i i which these acids will give superior results. HALIDSSFROM ALCOHOLS. Isopropyl bromide is formed rc+~lily from isopropyl alcohol and aqueous hydrobromic acid \\.hi.ti alkanesulfonic acids are used as eat,alysts.
PREPARATION OF ISOPROPYL BROMIDE. Two 11101~s 1,340 grams) of 48% hydrobromic acid, 1 mole (GO grams) of isopropl-l alcohol, and 0.6 mole (60 grams) of mixed 90% alkanesulfoiiic acid wcre p u t in a 1-liter flask provided with standard taper riech. A 15 X 400,mm. adiabatic column packed with helices was connected t o the flask, and the temperature of the boiling flask wync raised until isopropyl bromide began t o distill off. The bromidt. wm taken off until no more would come over. T h e raw bromid(3 was washed with concentrated sulfuric acid which removed sonic rtlcohol and ether. Yield of pure isopropyl bromide n-as 879; 01 theory based on the alcohol charged. T h e loss was unrcactid alcohol and ether. DERIVATIVES
ACID C H L O R I D IThe ~ usual method of preparing dkaneouifonyl chlorides is t y react the salts of the acids n-ith phosphorus pcntachloride ( I , 2, 6 ) or thionyl chloride (3). T h e n thc' frw sulfonic acids are used instead, thionyl chloride and phosphorus trichloride are satisfactory rragcnts for the synth chlorides. RS03H
3RS03H
+ SOC1, +RSO2Cl
SO, t HCI
+ 2PC13 +3RSOpC1 + P,Oa + 3H('l
The sulfonic acid is heated \\-it11 either of the two rtxagents in c'scess of the stoichiometric amount undtxr reflux until hydrogen chloride evolution ceases. The alkanesulfonyl chloride is then recovered from the reaction mixture by fractional distillation under reduced pressure. COIIVERSIOS TO SULFOKYL CHLORIDE.Two and one-tenth moles of 95yc methanesulfonic acid and 3.5 moles of phosphorus trichloride were mixed and refluxed gently in a 1-liter boiling flask connected by standard taper joints to a condenser. T h e temperature was raised very slowly from 30" C. t,o about, 80" C. When hydrogen chloride evolution became quite slow (about 5 hours) the reaction mixt'ure was removed from the heater and allowed to srttle. It was decanted from t,hP xriscous yel1oIv acid
S.Ai,,ra OF A i ~ ~ i-ilcrus. ~ -1 ~ large ~ nutiitiei~ ~ ot'b sitlts ~ of ~ the> alkanesulfonic acids were prepared. All of them (rcgartlle~s ( i f thc nature of the cation) w r e found to be highly solublts iii n-atcxr, and many of t,lieni are also soluble in common organic sol-
~
buch as acetonc, and methyl and ethyl alcohols. Thix AIJIUt)ilitics of the calcium, barium, and lead salts in water \ v ( * r dc~~ tc~rniiiied clii:iiititativel!-, and were found to dcpend upon the l(~ngth01' t hc> alkyl group. The niethanesulfonic acid salt' of t h e s ~m c t a l ~a r c less soluliltb than the correspondirig etliaIicdi m i c acid .-;tits, possibly bilcause thcy m sult:+tes. I.cad 1)urancaulfonatc is a1.o le i~eqiiiiidiiig(xt hancrulfonate; this inclicat viiiiig ol t,he carbon chain contributes to lon-er water solubility. I n gc.ncra1, the ethanesulfonates appear t o he more xvater ~olutilc t e of 1017-er or higher sulfonic acid.. than thc corresponding Its are given in Table 1-1. The solubilities of variou Most if not, all of the salts of these lower alkanesulfoiiic avidr form various hydrates, and in this respect re.wmble the metal hu1fates. Of the salts so far csamined, a few form hydrates \vhich ai'e +table :it quite high temperatures. For example, thc ni;tgncxeium d t s of nictliane- and ethancsulfonic acids form dihydratw ivhich :ire stable at 140" C. and possibly higher. These salts may firid application a: efficient drying and dehydrating agents. vcbnty,
ELECTROPLATING
The po.jsible usei of alkanesulfonic acids in electruplat iiig tiatlis are being investigated a t Battelle Aleinnrial Institutc. (;ood plates of copper, zinc cadmium, lead, nickel, and silver have t i w n olJtaincd, and a study of plating with chromium is in progrws. In addition t o the potentialities for electroplating, thehv acids iiiaj- prove t o have utilit5- in the electroforming of variou.; motal, -for esample, iron. Based on electroplating esperiments, tilo suitability of these acid-: for the elcctrorefining of lead and othrir metals also ~ e c ~ ~probablc. iis RIISCELLANEOUS USES
I n addition t o the applications indicated in the foregoing dismssion, a number of other possible uses for alkancxulfonic acids of low molecular n-eight have been suggested; a f e v of tliesc follo~v: catalysts for the dehydration of castor oil ( 4 ) ; catalysts for t h e isomerization a n d bodying of drj-ing oils: sours for tanning, laundering, and photographic solutions; sclcctive solvents for rhc removal of aromatics from paraffins, thinpene from benzene, and olefins from paraffins; solvents for csrrying out reactions such as chlorination, nitration, and oxidation; constituents of paint and varnish removcrs; soldering flux: and catalysts for the Fries rearrangement. ACKYOWLEDGXIEhT
The authors nish to acknonledge the asbistitnw of G. F. Itouault, D. E Burney, E. G. Ballmber, and B. 1,. Hill of thi5 lahoratorv in obtaining a portion of the data here presentcd. LITERATURE CITED
(1) BeiThoud. H d u . Chim. .detu. 12, %9 (1929). ( 2 ) Bilieter, Ber.. 38, 2019 (1905). (3) Boeseken and Tan Ockenburg. R e c . trar. chim., 33, :319 (1914). (4) Koninklijke Induatrieele Maatschappij v. h. Youry and van der Lande, N. V., French Patent 846,935 (Sept. 2 8 , 1930). ( 5 ) Marvel, Helfrick, and Belsley, J . Am. Chem. Soc., 51,1272 (1929). (6) Spring and Kinssinger, Ber., 15,445 (1882).
(7) Ibid., 16,326 (1883). (S) Suter, C. M., "The Organic Chemistry of Sulfur," Chap. 11. New York, John Wiley & Sons, 1943. (9) Vivian and Reid, J . Am. C h e m SOC., 57,2559 (1935). RECEIVED April 17, 1947.
4
~
~
