PHOTOCHEMICAL ADDITION OF SODIUM BISULFITE TO 1-OLEFINS CLARENCE 1. FURROW AND CHARLES E. STOOPS’
Research Division, Phillips Petroleum Co., Bartlesville, Okla. 74003 The free radical addition of sodium bisulfite to 1-olefins may be initiated by ultraviolet light. Yields in this two-phase system are strongly dependent upon the choice of cosolvent, and are markedly improved by the inclusion of certain ketones, aromatic hydrocarbons, or dyes. Some relationship between performance and structure of these promoters can be observed. Yields are also dependent upon concentration, cosolvent-water ratio, and bisulfite-olefin mole ratio.
THEanti-Markownikoff character of the free radical addition of bisulfite t o olefins was established by Kharasch and coworkers in the 1930’s (Kharasch et al., 1938). I n the past, the reaction has been initiated by dissolved oxygen or by added free radical agents. I t may be initiated by ultraviolet light (Furrow, 1967; Furrow and Stoops, 1967; Furrow etal., 1967). A relatively low yield of sodium hexanesulfonate was reported with initiation by gamma irradiation (Stogryn and Argabright, 1960). The previously unreported photochemical addition of bisulfite to olefins is the subject of the present report. The data presented here were derived from experiments with 1-dodecene. However, additional work has shown that other 1-olefins exhibit very similar reactivities.
n-amyl, isobutyl is superior to isopropyl and to isoamyl. Among alcohols of a given carbon number, the relative performance ranking is the same-i.e., the order of descending performance is tertiary, normal, iso- in so far as isomer possibilities permit. Since tert-butyl alcohol is clearly the cosolvent of a choice, it was employed as the cosolvent in all subsequent experiments. The heterogeneity of the reaction mixture declined with progress of the reaction. The reaction mixtures became homogeneous as soon as sulfonate accumulation approximated yields of 60 to 7 0 7 . Thus, the reaction mixtures were homogeneous during a substantial portion of the reaction period in experiments providing yields, for example, of 90% and above.
Cosolvents
Experimental
The reaction mixture comprises both an organic (olefin) and an aqueous (bisulfite) phase. I t is customary to include a polar organic (an amine, an ether, or usually an alcohol) as a cosolvent to promote reaction by facilitating contact between the two phases. However, all polar organics are not equivalent. A high yield requires the selection of a cosolvent that is appropriate for the initiator being employed, ultraviolet light in this investigation. The relative performance of alcohols that were evaluated as cosolvents is indicated in Table I. Of these, tert-butyl alcohol is clearly the most appropriate cosolvent. Moreover, each individual butyl isomer outperforms its corresponding homologs-e.g., n-butyl is superior to n-propyl and t o
Present address, University of Toledo, 2801 W. Bancroft, Toledo, Ohio 43606 I
Table I. Evaluation of Alcohols as Cosolvents Yield, Alcohol tert-Butyl n-Butyl n-Propyl see-Butyl Isobutyl Isopropyl Ethyl tert-Amyl n-Amyl Isoamyl Methyl
26
I&EC
P R O D U C T RESEARCH
R
of Theory
75.7 14.4 13.2 6.5 5.7 3.6 3.1 1.7 1.4 1.0 0.5
AND
DEVELOPMENT
Evaluation of Cosolvents (Representative Experiment). A 1-liter Morton resin flask was fitted with a mechanical stirrer, thermometer, and a quartz thimble holding a 100watt mercury vapor lamp (Hanovia 608A-36). The flask was cooled by tap water. Sodium bisulfite [52.0 grams (0.5 mole), Mallinkrodt analytical reagent], 1-dodecene [67.2 grams (0.4 mole), Aldrich Chemical Co.], water (280 ml.), and tert-butyl alcohol (280 ml., J. T . Baker analyzed reagent) were added to the flask. The rapidly stirred mixture was irradiated for 24 hours a t 35-36°C. The irradiated mixture was evaporated on a steam bath and then oven-dried a t 99” C. to constant weight. The sulfonate content of the reaction mixture was determined by ASTM Method D1681-59T. Product mixture: 105.9 grams, 77.9YC sulfonate, 75.7% yield. Promotion by Aromatic Hydrocarbon (Representative Experiment in Rayonet Photochemical Reactor). A 500-ml., 4-necked quartz flask was fitted with a mechanical stirrer, a thermometer, a condenser, and two “cold fingers” (for temperature control). The flask was centered in the cavity of a Rayonet Srinivasin-Griffin photochemical chamber reactor (Southern N. E. Ultraviolet Co., Middletown, Conn.). Sodium bisulfite [31.2 grams (0.3 mole), Mallinkrodt analytical reagent], l-dodecene (40.4 grams, 0.24 mole, Aldrich Chemical Co.), water (170 ml.), tert-butyl alcohol (170 ml.), and anthracene (0.005 gram, purified by alumina column chromatography) were charged t o the flask. The mixture was stirred rapidly and irradiated (sixteen 2537-A. lamps) a t 33°C. for 4.5 hours. T h e irradiated mixture was treated as in experiment described above. Product mixture: 63.8 grams, 80.5% sulfonate, 78.7% yield.
Base Line Conditions
Table I1 outlines the experimental conditions that served as standard-Le., as the base line-for the other experiments discussed below. The Rayonet photochemical reactor is essentially a reflecting cylinder with 16 ultraviolet lamps symmetrically arranged around the periphery. The reaction vessel, a 500-ml., stirred, quartz flask was placed a t the center of the reactor. The lamps employed in the experiments discussed below were mercury vapor lamps of principal output a t 2537 A. (Other lamps-e.g., 3500-A. and daylight fluorescent-gave basically similar results.) The yield afforded under these conditions was 11.9% of theory-Le., 11.9% of the dodecene was converted to sodium 1-dodecanesulfonate. Volatiles were removed on a steam bath. They were not examined nor was the inorganic portion of the evaporation residue. T h a t sodium 1-dodecanesulfonate was the only carbon compound in the evaporation residue was demonstrated by concurrence of the actual sodium 1-dodecanesulfonate content determined by ASTM Method D1681-59T with sodium 1-dodecanesulfonate content calculated from carbon analysis on the basis that all carbon present is there as sodium 1-dodecanesulfonate.
absorbance itself is, significantly, not the controlling factor. Relative promotional abilities clearly do not relate to ease of forming the ketone-sodium bisulfite adduct. Phenyl ketones, diketones, and other keto compounds are relatively poor promoters. Table I V shows the effect on yield of progressive substitution of 2-butanone for tert-butyl alcohol. The reaction may also be promoted by the inclusion of small amounts of aromatic hydrocarbons (Table V). With the exception of anthracene, the promotional effect increases as structurally more complex aromatics are employed. The comparison was made a t a hydrocarbon absorbance value of 16, the absorbance afforded by the most effective aromatic (anthracene) at its optimum concentration ( 5 mg. present under otherwise base line conditions). As with ketone promoters cited above, yield differences a t this ultrahigh absorbance level indicate that absorbance itself is not the controlling factor. Table VI indicates that this generalization also holds as the condi-
Table IV. Effect on Yield of Progressive Substitution of 2-Butanone for tert-Butyl Alcohol
Vol
cc
Substitution
Promotional Effects
Table II. Standard Conditions
Evaluation a t absorbance value of 16
Yield, % of Theory 15 uol. C/f
Me-CO-Et Et-CO-Et Me-CO-Me CH?(CH,),CO Me-CO-tert-Bu Me-CO-OMe Ph-CO-Ph Me-CO-0-CO-Me Me-CO-CO-Me Me-CO-Ph Me-CO-H Me-CO-CHl-CO-Me None
substitution for tert-BuOH (25 ml.)
Absorbance value of 7.84
91.2 77.3 76.4 76.2 72.9 8.5
95.1 35.2 36.5
3.5 2.7 1.3 1.2 1.o 11.9
11.9 88.8 95.6 91.3 71.4 38.6 11.0 2.7 1.9 1.o 0.5
Table V. Promotional Effects of Aromatic Hydrocarbons
40.4 g. (0.24 mole) 31.2 g. (0.3 mole) 170 ml. 170 ml. 330 c. 4.5 hr. reactor
Table 111. Promotional Effects of Carbonyl Compounds
Carbonyl Compound
Yzeld, of Theorj
0 10 20 30 40 50 60 70 80 90 100
Partial substitution of dialkyl ketones for cosolvent tertbutyl alcohol raised the yield of sodium l-dodecanesulfonate markedly (Table 111).Substitution was made either on a 15 volume c;b basis or on the basis of a constant ketone absorbance value of 7.84, which is the absorbance afforded by 2-butanone (grossly the most effective carbonyl promoter) a t optimum concentration. Yield differences a t this ultrahigh absorbance level indicate that
1-Dodecene Sodium bisulfite tert-Butyl alcohol Water Temperature Reaction time 2537-A. Rayonet photochemical Base line yield, 1 1 . 9 5 of theory
cc
Wt., G. 27.0 33.8 41.6
13.3
0.0447
1.5
0.1985
14.5 11.9
0.1483
Hydrocarbon
Wt., G.
Anthracene C hrysene Pyrene Naphthacene Phenanthrene p-Terphenyl Saphthalene Biphenyl Kone Benzene
0.0050 0.0289 0.0456 0.2150 0.0198 0.0919 0.2500 0.0601 4.8000
cc
Yield, of Theor3 78.7 60.5 50.4 45.5 41.8 28.0 27.4 19.5 11.9 2.0
Table VI. Dependence of Yield upon Anthracene
G.
N o . of Lamps
Hours
0.05 0.005 0.0005 None 0.05 0.005 None 0.05 0.005 None
16 16 16 16 16 16 16 1 1 1
4.5 4.5 4.5 4.5 3.0 3.0 3.0 4.5 4.5 4.5
Anthracene,
VOL. 7
Yieid, of Theoq
69.8 78.7 49.0 11.9 38.1 40.0 8.9 16.8 17.5 8.7
NO. 1 M A R C H 1968
27
tions are made more sensitive through shortening the irradiation time or reducing the light intensity. Certain dyes also promote the photochemical addition of sodium bisulfite to 1-olefins. The comparison in Table VI1 was made a t a dye absorbance value of 0.163, the absorbance of Rose Bengal (grossly, the most effective dye) a t the minimum concentration that affords maximum promotional effect. This dependence of yield upon quantity of Rose Bengal is shown in Table VIII. In simplest terms, the yields are not improved by more than approximately 3 mg. of Rose Bengal, but neither are they suppressed (as might be anticipated from the resulting increase in absorbance).
Other Variables Table I X contrasts the effects upon sulfonate yield of reductions in light intensity and time of irradiation. The light intensity can be cut (by symmetrical removal of lamps) by a factor of ?4 without depressing the yield. However, cutting the irradiation time by a factor of ?4 causes a marked decline in yield even with the larger quantity of Rose Bengal present. In sum, sulfonate yield
is more dependent upon time than upon light intensity under these conditions. This same relation is shown a little differently in Table X. High light intensity-short time and low light intensity-long time experiments are involved; the yield is lower by a factor of 2/3 in the high light intensity-short time experiment. This effect may be basically mechanical. With light adsorption largely confined to a thin envelope just inside the flask wall, the effect may be largely a requirement of providing time sufficient to move the reaction mixture thoroughly through this envelope. In investigating other parameters, it was found that, a t constant volume, experiments made with proportionally less bisulfite-olefin mixture yielded more sulfonate (Table X I ) . This percentage improvement may be ascribed to the facts that the heterogeneity of the reaction mixture becomes less of a factor under more dilute conditions and that proportionally better illumination of the reaction mixture results from decreased absorbance. The one-to-
Table X. Light Intensity vs. Time at 18 lamp-Hours at 0.003 G. of Rose Bengal
N o . of Lamps
Hours
Si of Theory
16 4
1.125 4.5
26.3 77.3
Table VII. Promotional Effects of Dyes Evaluation a t absorbance value of 0.163
Yield,
Yield, Dye Rose Bengal S.O. 687 Phosphine R Eosin Y Fluorescein, disodium salt Resazurin Pararosanilin hydrochloride Methylene blue None Metanil yellow
W t . , G. 0.0030 0.0031 0.0018 0.0017 0.0009 0.0036 0.0011
...
0.0026
% of Theory 77.0 76.7 75.3 63.7 25.3 22.5 21.6 11.9 8.4
Table VIII. Dependence of Yield upon Quantity of Rose Bengal
Rose Bengal, G.
Yield. R o f Theory
0.2000 0.0500 0.0050 0.0027 0.0006 None
77.0 76.2 75.5 77.9 22.4 11.9
Table XI. Dependence of Yield upon Concentration In presence of 0.005 g. Rose Bengal
Concn. Factor Relatiue to Concn. under Standard Conditions, Table I I
5; of Theory
1.275 1.000 0.537 0.280
76.2 79.8 83.8 96.7
Table XII. Dependence of Yield upon Volume Ratio of ferf-Butyl Alcohol to Water In presence of 0.005 g. Rose Bengal
Table IX. Relative Dependence of Yield upon light Intensity and Time
Factor 1.0 0.5 0.25 0.125 0.0625
No. of Lamps 16 8 4 2 1
Rose Bengal, G. 0.003 0.003 0.003 0.003 0.003
Yield, 77.9 76.3 77.3 65.7 52.3
28
4.5 2.25 1.125
0.05 0.05 0.05
76.2 63.8 34.2
I & E C PRODUCT RESEARCH A N D DEVELOPMENT
Volume Ratio tert-B u O H H 2 0
5 of T h e 0 0
Yield,
0.498 0.626 0.753 1.000 1.500 2.000
22.2 61.3 79.2 79.8 76.7 75.5
Table XIII. Dependence of Yield upon Bisulfite-Dodecene Mole Ratio
% of Theory
Hours 1.00 0.50 0.25
Yield,
With 20 vol.
-C
substitution of 2-butanone for tert-butyl alcohol
Mole Ratio, Bisulfite- Dodecene 1.000 1.250 1.666 2.500
Yield, 9; of Theory 79.4 95.6 98.4 100.9
Table XIV. Progress of Reaction with Time With 20 vol. "0 substitution of 2-butanone for tert-butyl alcohol
Time, H r 0.375 0.75 1.50 2.25 3.00 4.50
Yield, of Theory 5.0 11.2 39.4 73.5 89.7 95.6
one volume ratio of tert-butyl alcohol t o water was essentially optimum (Table X I I ) . The importance of employing excess sodium bisulfite is indicated in Table X I I I . I n the presence of methyl ethyl ketone, complete conversion of olefin to bisulfite effectively occurs a t a bisulfitedodecene mole ratio of 2.5. The photochemical addition of sodium bisulfite to 1-olefins begins without a detectable induction period. The reaction rate increases (Table XIV) as the accumulation
of product affords a solubilizing effect upon the reactants. The reaction eventually slows with the depletion of the olefin. Acknowledgment
Gratitude is due C. F. Cook and J. P. Guillory for their interest and suggestions. literature Cited
Furrow, C. L., U. S. Patent 3,336,210 (1967). Furrow, C. L., Stoops, C. E., U. S. Patent 3,342,714 (1967). Furrow, C. L., Stoops, C. E., Mahan, J. E., U. S.Patent 3,337,437 (1967). Kharasch, M. S., May, E. M., Mayo, F . R., J . Org. Chem. 3, 175 (1938). Stogryn, E. L., Argabright, P. A., Ger. Patent 1,090,198 (Oct. 6, 1960). RECEIVED for review August 7, 1967 ACCEPTED November 16, 1967 Division of Petroleum Chemistry, 153rd Meeting, ACS, Miami, Fla., April 1967.
A TUNGSTEN OXIDE ON SILICA CATALYST FOR PHILLIPS' TRIOLEFIN PROCESS 1. F. HECKELSBERG, R. 1. BANKS, AND G. C. BAILEY
Phillips Petroleum Co., Bartlesdle, Ohla. A catalyst consisting of tungsten oxide on silica that disproportionates olefins at relatively high temperatures will disproportionate propylene with equilibrium conversions ( 4 5 % ) and high efficiencies to ethylene and butenes at 600°F. or higher, 450-p.s.i.9. pressure, and space rates of 20 to 60 WHSV. N o special pretreatments are required and the catalyst shows considerable resistance to common poisons such as air and water.
ANIMPORTANT new catalytic reaction has been reported from the research laboratories of Phillips Petroleurn Co., in which linear olefins of three to eight carbon atoms were disproportionated to homologs of shorter and longer carbon chains (Banks, 1961, 1963, 1966; Banks and Bailey, 1964)-for example, propylene was disproportionated to give ethylene and the 2-butenes. Catalysts for this reaction were reported to be molybdenum hexacarbonyl, tungsten hexacarbonyl, or molybdenum oxide supported on alumina. These catalysts operated in the temperature range of 200" to 400" F. Recently Bradshaw, Howman, and Turner have reported on olefin disproportionation reactions using molybdena-alumina catalysts (1967). Further investigations of catalysts have resulted in the discovery of another
catalyst, tungsten oxide on silica, having excellent disproportionation activity (Heckelsberg, 1963, 1965). This catalyst, however, operates best in the temperature range of 500" to 1000" F. For commercial applications operation in this temperature range offers resistance to poisons and reduces or eliminates costly and time-consuming cooling and heating periods during regeneration. This paper discusses the properties of this catalyst. Experimental Methods
Catalysts. The catalysts were prepared by impregnating various silicas with water solutions of ammonium tungstate. A number of commercial silicas and several VOL. 7 N O . 1 M A R C H
1968
29
