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Liquid-phase oxidation of p-toluic aldehyde by molecular oxygen in acetic acid
150
G. S. GOLUBEVe$ a~.
6. Placty Resinas 7, No. 36, 1965 7. Yu. K. YUR'EV, Prakticheskiye raboty po organicheskoi khlmii (Practical Studies on Organic Chemistry). I-II, Moscow, 1964 8. E. BERNATE, E. KARLSEN and T. LEDAAL, Acta Chem. scand., No. 21, 1229 1967 9. S. D. RAZUMOVS~H~ A. A. KEFELI, G. R. TRUBNIKOV and G. Ye. ZATKOV,
Dok]. AN SSSR 192, 1313, 1970 10. S. D. RAZUMOVSKH and G. Ye. ZAIKOV, Izv. AN SSSR, Ser. khirn, 686, 1971 11. GUBEN-VEIL', Metody organicheskoi ~rhlm~i (Methods in Organic Chemistry). 2, Gostoptekhizdat, 1963 12. Ye. T. DENISOV, Konstanty skorosti gomolitiehe~kikh zhidkofaznykh reaktsii (Rate Constants of Homolytic Liquid-phase Reactions). Nauka, Moscow, 1971 13. N. M. EMANUEL', Ye. T. DENISOV and Z. K. MEIZUS, Tsepnyye reaktsii okisleniya uglevodorodov v zhidkoi raze (Chain Reactions of Liquid-phase Oxidation of Hydro° carbons). Nauka, Moscow, 1965
LIQUID-PHASE 0NmATION OF p-TOLUIC ALDEHYDE BY MOLF.CULAR OXYGEN IN ACETIC ACID* G. S. GOLUBEV, V. N. ALEKSA_~DROV, ,V. V. K--0MIN and V. F. I%]A~OK An-Union Scientific Research and Design Insti$utm for Monomers
(Received 27 May 1974) THE s t u d y of oxidation of aldehydes, which are intermediate products in oxidation of alkyl-axomatic hydrocarbons to carboxylic acids, is of considerable interest and m a n y papers are concerned with this problem. Aldehydes are of decisive importance in catalytic initiation of oxidation [1-3]. W i t h o u t a catalyst, as shown in conjugate oxidation of toluene and benzaldehyde [4], aldehyde which oxidizes b y a chain mechanism m a y also ensure a high rate of conversion of toluene to benzoic acid [4]. At the same time in wellknown processes of oxidation of toluene [5], isomeric xylenes [6] and methylnaphthalenes [7] considerable amounts of aldehyde axe formed in spite of their ability to undergo auto-oxidation. Further, with oxidation of p-xy!ene in the presence of a manganese catalyst after the formation in the reaction mixture of a certain concentration of p-toluic aldehyde, the reaction is maxkedly inhibited [8]. All this points to specific features of oxidation of aromatic aldehydes. A s t u d y of these features by oxidation of 1~-toluic aldehyde was the object of this study. * Neftekhlmlya 15, No. 4, 593-596, 1975.
Liquid-phase oxida¢ion of p.tmluio aldehyde
161
EXPERIMENTAL
~ ~ToI~ C ~]d ~hyde S ~ ~hesized fro m ~O]u e ~
Lby ~h~ G ~ e r m ~ n ~ ox
reaction was used for oxidation. According to results of chromatographic analysis, it contained traces of ID-toluic acid and had a boiling point oi 103105°/10 mm. 98°/o acetic acid (chemically pure) was used as solvent. Cobalt and manganese acetates and ammonium bromide or their mixtures were used for the initiation of the reaction. Oxidation was carried out in a reactor with a stirrer at a pressure of 20 kg]cm ~ and an air consumption of 20 ml]min per 1. reaction mixture, while kinetic conditions were ensured for the reaction. Products of oxidation were a~alysed by gas-liquid chromatography and polarograph:( [9, 10]. RESULTS
The Table indicates (experiments 1-2) that p-toluic aldehyde is readily oxidized with atmospheric oxygen even without a catalyst, however, oxidation takes place mainly at the carbonyl group to p-toluic acid and the amount of terephthalic acid in reaction products is negligible. I t is interesting t h a t in all experiments at 120, 150 and 200 ° oxidation undergoes self-inhibition with a degree of aldehyde conversion of 80-85°/o. Inhibition is, apparently, due to the formation in the reaction mixture of inhibitors, the formation mechanism of which is not quite clear. I t m a y be assumed that during the breakdown of peracid cresol is formed (reaction (1)). This reaction competes with the reaction ot molecular conversion (2) and is negligible with high concentration of p-toluic aldehyde at the beginning of the process. CHa--C,tIa--COOOH -. [CH,--C,H,--COO'~-'OH] -. CH3--C,H,--OH-t-CO, (1) in the cell CH,--C,H~--COOOH~-CHa--C,H~--CHO -~ 2CH,--C,Hd--COOH
(2)
With a reduction of aldehyde concentration the rate of chain formation and the length of chains is reduced and the process is inhibited by the action of an inhibitor. The reaction was also inhibited by perbenzoic acid additives during catalytic oxidation of toluene and p-xylene [11] and the authors attributed this to the deactivation of the catalyst. For non-catalytic oxidation of la-toluic aldehyde this explanation, however, is not valid. I n the presence of bromine or cobalt salts the rate of oxidation of p-toluic aldehyde increases slightly ( T a b l e ) a n d inhibition is observed at a more advanced stage. For ammonium bromide the process, apparently, ceases after the conversion of all the bromine into a covalent-combined form or its elimination from the reaction zone, the inhibition mechanism being the same as for a non-catalyzed reaction. In the presence of cobalt acetate the formation of ID-cresol is not very likely and oxidation is considerably inhibited only with a degree of aldehyde conversion of over 95~/e, i.e. as a result of reduced reagent~
G. S. GOL~mEV Ot a/.
152
c o n c e n t r a t i o n . I n i t i a t i o n o f t h e r e a c t i o n b y t h e j o i n t a d d i t i o n of cobalt a n d b r o m i n e salts m a r k e d l y accelerates t h e process b y i n v o l v i n g a m e t h y l group. T h e use o f a c o b a l t - m a n g a n e s e - b r o m i d e c a t a l y s t also ensures a h i g h r a t e o f initiation of the reaction. RESULTS OF CATALYTICOXIDATIONOF p-TOLmC ALDEHYDE Amount of catalyst 2.73 X 10 -= mole/1. Maximum rate of
No. exper iment
Initiator
BrCo ~+ Co ffi+, B r -
7*
(Co=++M.n=+), B r -
8f 9 10* 11 12t
Tem- Induc - Reac pera- tion pe- tion c o n v e r sion of ~uro, riod, time, aldehy[ p-to°C min min to X 10-'1 luic nolo/1. X acid Xmin -
I 2 3 4 5 6
Degree of c o n . % of t h e initial
version,
Mn=+ Mn=+, B r M n I+ + Co I+ M n I+
Co"+
120 150 200
10 5 3
20.8 28-0 40.0
81 76 77
120 120 120 120 120 120 120
10 10 10 12
22.2 25.0
87
33-3
83
240 300 180
41.0 0 0
35
3.8
84 0 0 80
150 120
20 100
100 24
1.3 32.8
83
terephthalio acid
0"9 0"9
Not determined 2.7 5.2 9.7 4-5
0 0 Not determined
53
20
63.3
* CO : Mn ratio 1 : 1.
t The concentration of Mn=+varied within the range of 0.7+2.73 × 10-= mole/l. $ The concentration of Co=+is 1.37x 10-1 mole/l. A n i n t e r e s t i n g f e a t u r e of o x i d a t i o n o f p - t o l u i c a l d e h y d e is t h e i n h i b i t i n g a c t i o n o f m a n g a n e s e c o m p o u n d s (Table, e x p e r i m e n t s 8-11). I n t h e p r e s e n c e o f m a n g a n e s e a c e t a t e w i t h a c o n c e n t r a t i o n of 0 . 7 - - 2 . 7 3 × 1 0 -s mole/1, in p a r t i c u l a r , o x i d a t i o n did n o t s t a r t for 240, a f t e r which t h e e x p e r i m e n t s were discontinued. T h e p r e s e n c e in t h e c a t a l y s t of a m m o n i u m b r o m i d e ( e x p e r i m e n t 9) does n o t e l i m i n a t e t h e i n d u c t i o n period. T h e i n d u c t i o n period is e l i m i n a t e d or r e d u c e d o n l y b y t h e a d d i t i o n of cobalt ( e x p e r i m e n t 10), cobalt and b r o m i n e ( e x p e r i m e n t 7) a n d a n increase of t e m p e r a t u r e ( e x p e r i m e n t 11). Chain r u p t u r e on t h e c a t a l y s t m a y be visualized b y r e a c t i o n (3). As s h o w n b y o x i d a t i o n o f e t h y l b e n z e n e , t h e r a t e c o n s t a n t of i n t e r a c t i o n of t h e p e r o x y radical w i t h Mn +2 is 3 t i m e s g r e a t e r t h a n w i t h Co +s [12]. F u r t h e r , w i t h cobalt an a c t i v e f o r m of c a t a l y s t is created, which is c a p a b l e of i n i t i a t i n g a n e w chain
Liquid.phase oxidation o f ;o-toluie aldehyde
153
of oxidation (reactions (4)-(6)), whereas I~n+8 interacts with aldehyde at a relatively low rate. I t should also be considered t h a t reaction (3) competes with the reaction of chain extension in oxidation (7). Ar*COOO'+Mo+' ~ [ArCOOO-Mo+']
(3)
[ArCOOO-Mo+'] +ArCHO -~ ArCOOH+ [ArCOO-Mo+s]
(4)
[ArCOO-Me+*]+ArCHO -~ ArCOOH+ [ArCO...Me+t]
(5)
[ArCO...Mo +') +O, -+ [ArCOOO-Mo +s]
(6)
ArCOOO'+ArOHO --, ArOOOOH+ArCO
(7)
The ratio of rates of reactions (3)-(7), which depends on catalyst composition and concentration and those of aldehyde, accounts for the inhibition or development of the process. I n fact, on increasing the initial concentration of the cobalt catalyst to 1.37 × 10 -1 mole/l, we also observed an induction period (Table, experiment 12), but oxidation only commenced after the complete transition of cobalt into the trivalent form. SUMMARY
1. I t was established t h a t in non-catalytic oxidation of p-toluic aldehyde at a temperature of 120-200 ° the reaction is self-inhibited with a degree of aldehyde conversion of 80-85%. I t was assumed t h a t p-cresol formed during the thermal conversion of pertoluie acid is the inhibitor. 2. I t was shown t h a t during oxidation of p-toluie aldehyde in the presence of a bromine compound the reaction is non-catalytic. 3. At certain critical concentrations catalysts of liquid-phase oxidation of hydrocarbons function as effective inhibitors in the case ofp-toluic aldehyde. REFERENCES 1. A. M. IVANOV, L. N. lgH~.kl,O and K. A. CHEItVINSKII, ~eftekhimiya 9, 260,
1969 2. N. Ye. C~REPANOVA, K. A. (~[I~ltVINSKII and L. N. KH~KALO, ~him. tekhnol. Resp. mezhved, n.-tekhn, sb. 9, 48, 1967 3. Ya. MOTOTAKE, F. TAIDZO, N. KHIROSI and I. TATSUYA, Koge kagaku dza~i 71, 217, 1968 4. A. M. IVANOV and V. V. TSISAI~UK, Neft,okhlrniya 12, 748, 1972 5. N. G. DIGUROV, V. A. SEDLYAROV, N. N. LEBEDEV and Ys. V. NASTYUKOVA, Nei~kh;miya 9, 552, 1969 6. V. N. JtLI~.K~IA_NDROV,G. S. GOLUBEV, S. S. GITIS, V. V. KHOMIN and N. V. NOVORUSSKAYA, ]~himiya i tekhnol monomerov. Tr. Vses. n..i. i proyektn, in.is taChOmeter 2, 6, 1970 7. V. K. KONDRATOV and N. D. RUS'¥ANOVA, Neftekhlmlya 12, 725, 1972 8. V.N. ALRK~IANDROV,V. V. 1RHOM][N,S. S. GITIS and G. S. GOLUBEV,~ei~Ichimiya 12, 737, 1972 9. Ye. M. K A ~ N. V. NOVORUSSKAYA and V. N. ALEKSAN])ROV, Zh. a, AI;~. khimii 24, 1881, 1969
1~4
M.S. SAZ,U~HOVet al.
10. G. M. GAL'PERN, V. A. IL'INA, P. M. SHUMSKAYA and V. N. ALEgSANDROV, Khlmlya i tekhnol, monomerov. Tr. Vses, n.-i. i proektn, in-t. monomerov 2, 129, 1970 11. A. M. IVANOV, L. N. KHAKALO and K. A. ~CHEItVINSKII, Neftel~hlmiya 8, 589, 1968 12. Ye. M. TOCHINA, L. M. POSTNIKOV and V. Ya. SHLYAPINTOKH, Izv. AN SSSR, Ser. khlm. 71, 1968
OXIDATIVE CHLORINATION OF ETHYLBENZENE AND ISOPROPYLBENZENE* M. S. SAT,A~I~[OV,~V~.~¢~.GUSS]~I~OV,CH. A. CH~,A~IEV and D. K. ABD~LAYEV Stungait Branch of the Institute of Petrochemical Processes Azerb. S.S.R. Academy of Sciences (Received 16 July, 1974)
C ~ o ~ x ~ . derivatives of ethyl and isopropylbenzene are obtained b y alkyiatiou of chlorobenzene in the presence of Friedel-Crafts [1, 2] catalysts b y direct chlorination of ethylbenzene [3-5] and isopropylbenzene [6, 7]. A1Cls, FeCIa, ZnCI~, SnC14 and TiC14 are used as catalysts in chlorination of alkylbenzenes. However, secondary reactions [5, 7] are undesirable in the catalytic process of chlorination. Investigations are being carried out in our laboratory in the field of oxidizing chlorination of alkyl-aromatic hydrocarbons [8]. There is no information in the literature about this problem. • This article is concerned with explaining some relations which govern the preparation of chlorine derivatives of ethyl- and isopropy!benzene b y oxidative chlorination (with a mixture o f hydrochloric acid and hydrogen perox i d e ) . ..... Experiments were carried out in a glass flask provided with a mechanical atirrer, d r o p funnel and a thermometer. Reaction temperature was maintained with an accuracy of ± 0 . 5 °. Commercial hydrochloric acid, ethyl- and isopr0pylbenzene (pure) and a 30% aqueous solution of hydrogen peroxide were used: for the investigation. The flask was filled with these in given proportions. Hydrogen peroxide was added to the reaction mass from a drop funnel. ~ The react:ion mixture was analysed a t equal time intervals b y GLC using an LKhM-7A device with a heat conductivity detector (detector current 90 mA). * Neftekhlrnlya 15, No. 4, 601-605, 1975.
G. S. GOLUBEVe$ a~.
6. Placty Resinas 7, No. 36, 1965 7. Yu. K. YUR'EV, Prakticheskiye raboty po organicheskoi khlmii (Practical Studies on Organic Chemistry). I-II, Moscow, 1964 8. E. BERNATE, E. KARLSEN and T. LEDAAL, Acta Chem. scand., No. 21, 1229 1967 9. S. D. RAZUMOVS~H~ A. A. KEFELI, G. R. TRUBNIKOV and G. Ye. ZATKOV,
Dok]. AN SSSR 192, 1313, 1970 10. S. D. RAZUMOVSKH and G. Ye. ZAIKOV, Izv. AN SSSR, Ser. khirn, 686, 1971 11. GUBEN-VEIL', Metody organicheskoi ~rhlm~i (Methods in Organic Chemistry). 2, Gostoptekhizdat, 1963 12. Ye. T. DENISOV, Konstanty skorosti gomolitiehe~kikh zhidkofaznykh reaktsii (Rate Constants of Homolytic Liquid-phase Reactions). Nauka, Moscow, 1971 13. N. M. EMANUEL', Ye. T. DENISOV and Z. K. MEIZUS, Tsepnyye reaktsii okisleniya uglevodorodov v zhidkoi raze (Chain Reactions of Liquid-phase Oxidation of Hydro° carbons). Nauka, Moscow, 1965
LIQUID-PHASE 0NmATION OF p-TOLUIC ALDEHYDE BY MOLF.CULAR OXYGEN IN ACETIC ACID* G. S. GOLUBEV, V. N. ALEKSA_~DROV, ,V. V. K--0MIN and V. F. I%]A~OK An-Union Scientific Research and Design Insti$utm for Monomers
(Received 27 May 1974) THE s t u d y of oxidation of aldehydes, which are intermediate products in oxidation of alkyl-axomatic hydrocarbons to carboxylic acids, is of considerable interest and m a n y papers are concerned with this problem. Aldehydes are of decisive importance in catalytic initiation of oxidation [1-3]. W i t h o u t a catalyst, as shown in conjugate oxidation of toluene and benzaldehyde [4], aldehyde which oxidizes b y a chain mechanism m a y also ensure a high rate of conversion of toluene to benzoic acid [4]. At the same time in wellknown processes of oxidation of toluene [5], isomeric xylenes [6] and methylnaphthalenes [7] considerable amounts of aldehyde axe formed in spite of their ability to undergo auto-oxidation. Further, with oxidation of p-xy!ene in the presence of a manganese catalyst after the formation in the reaction mixture of a certain concentration of p-toluic aldehyde, the reaction is maxkedly inhibited [8]. All this points to specific features of oxidation of aromatic aldehydes. A s t u d y of these features by oxidation of 1~-toluic aldehyde was the object of this study. * Neftekhlmlya 15, No. 4, 593-596, 1975.
Liquid-phase oxida¢ion of p.tmluio aldehyde
161
EXPERIMENTAL
~ ~ToI~ C ~]d ~hyde S ~ ~hesized fro m ~O]u e ~
Lby ~h~ G ~ e r m ~ n ~ ox
reaction was used for oxidation. According to results of chromatographic analysis, it contained traces of ID-toluic acid and had a boiling point oi 103105°/10 mm. 98°/o acetic acid (chemically pure) was used as solvent. Cobalt and manganese acetates and ammonium bromide or their mixtures were used for the initiation of the reaction. Oxidation was carried out in a reactor with a stirrer at a pressure of 20 kg]cm ~ and an air consumption of 20 ml]min per 1. reaction mixture, while kinetic conditions were ensured for the reaction. Products of oxidation were a~alysed by gas-liquid chromatography and polarograph:( [9, 10]. RESULTS
The Table indicates (experiments 1-2) that p-toluic aldehyde is readily oxidized with atmospheric oxygen even without a catalyst, however, oxidation takes place mainly at the carbonyl group to p-toluic acid and the amount of terephthalic acid in reaction products is negligible. I t is interesting t h a t in all experiments at 120, 150 and 200 ° oxidation undergoes self-inhibition with a degree of aldehyde conversion of 80-85°/o. Inhibition is, apparently, due to the formation in the reaction mixture of inhibitors, the formation mechanism of which is not quite clear. I t m a y be assumed that during the breakdown of peracid cresol is formed (reaction (1)). This reaction competes with the reaction ot molecular conversion (2) and is negligible with high concentration of p-toluic aldehyde at the beginning of the process. CHa--C,tIa--COOOH -. [CH,--C,H,--COO'~-'OH] -. CH3--C,H,--OH-t-CO, (1) in the cell CH,--C,H~--COOOH~-CHa--C,H~--CHO -~ 2CH,--C,Hd--COOH
(2)
With a reduction of aldehyde concentration the rate of chain formation and the length of chains is reduced and the process is inhibited by the action of an inhibitor. The reaction was also inhibited by perbenzoic acid additives during catalytic oxidation of toluene and p-xylene [11] and the authors attributed this to the deactivation of the catalyst. For non-catalytic oxidation of la-toluic aldehyde this explanation, however, is not valid. I n the presence of bromine or cobalt salts the rate of oxidation of p-toluic aldehyde increases slightly ( T a b l e ) a n d inhibition is observed at a more advanced stage. For ammonium bromide the process, apparently, ceases after the conversion of all the bromine into a covalent-combined form or its elimination from the reaction zone, the inhibition mechanism being the same as for a non-catalyzed reaction. In the presence of cobalt acetate the formation of ID-cresol is not very likely and oxidation is considerably inhibited only with a degree of aldehyde conversion of over 95~/e, i.e. as a result of reduced reagent~
G. S. GOL~mEV Ot a/.
152
c o n c e n t r a t i o n . I n i t i a t i o n o f t h e r e a c t i o n b y t h e j o i n t a d d i t i o n of cobalt a n d b r o m i n e salts m a r k e d l y accelerates t h e process b y i n v o l v i n g a m e t h y l group. T h e use o f a c o b a l t - m a n g a n e s e - b r o m i d e c a t a l y s t also ensures a h i g h r a t e o f initiation of the reaction. RESULTS OF CATALYTICOXIDATIONOF p-TOLmC ALDEHYDE Amount of catalyst 2.73 X 10 -= mole/1. Maximum rate of
No. exper iment
Initiator
BrCo ~+ Co ffi+, B r -
7*
(Co=++M.n=+), B r -
8f 9 10* 11 12t
Tem- Induc - Reac pera- tion pe- tion c o n v e r sion of ~uro, riod, time, aldehy[ p-to°C min min to X 10-'1 luic nolo/1. X acid Xmin -
I 2 3 4 5 6
Degree of c o n . % of t h e initial
version,
Mn=+ Mn=+, B r M n I+ + Co I+ M n I+
Co"+
120 150 200
10 5 3
20.8 28-0 40.0
81 76 77
120 120 120 120 120 120 120
10 10 10 12
22.2 25.0
87
33-3
83
240 300 180
41.0 0 0
35
3.8
84 0 0 80
150 120
20 100
100 24
1.3 32.8
83
terephthalio acid
0"9 0"9
Not determined 2.7 5.2 9.7 4-5
0 0 Not determined
53
20
63.3
* CO : Mn ratio 1 : 1.
t The concentration of Mn=+varied within the range of 0.7+2.73 × 10-= mole/l. $ The concentration of Co=+is 1.37x 10-1 mole/l. A n i n t e r e s t i n g f e a t u r e of o x i d a t i o n o f p - t o l u i c a l d e h y d e is t h e i n h i b i t i n g a c t i o n o f m a n g a n e s e c o m p o u n d s (Table, e x p e r i m e n t s 8-11). I n t h e p r e s e n c e o f m a n g a n e s e a c e t a t e w i t h a c o n c e n t r a t i o n of 0 . 7 - - 2 . 7 3 × 1 0 -s mole/1, in p a r t i c u l a r , o x i d a t i o n did n o t s t a r t for 240, a f t e r which t h e e x p e r i m e n t s were discontinued. T h e p r e s e n c e in t h e c a t a l y s t of a m m o n i u m b r o m i d e ( e x p e r i m e n t 9) does n o t e l i m i n a t e t h e i n d u c t i o n period. T h e i n d u c t i o n period is e l i m i n a t e d or r e d u c e d o n l y b y t h e a d d i t i o n of cobalt ( e x p e r i m e n t 10), cobalt and b r o m i n e ( e x p e r i m e n t 7) a n d a n increase of t e m p e r a t u r e ( e x p e r i m e n t 11). Chain r u p t u r e on t h e c a t a l y s t m a y be visualized b y r e a c t i o n (3). As s h o w n b y o x i d a t i o n o f e t h y l b e n z e n e , t h e r a t e c o n s t a n t of i n t e r a c t i o n of t h e p e r o x y radical w i t h Mn +2 is 3 t i m e s g r e a t e r t h a n w i t h Co +s [12]. F u r t h e r , w i t h cobalt an a c t i v e f o r m of c a t a l y s t is created, which is c a p a b l e of i n i t i a t i n g a n e w chain
Liquid.phase oxidation o f ;o-toluie aldehyde
153
of oxidation (reactions (4)-(6)), whereas I~n+8 interacts with aldehyde at a relatively low rate. I t should also be considered t h a t reaction (3) competes with the reaction of chain extension in oxidation (7). Ar*COOO'+Mo+' ~ [ArCOOO-Mo+']
(3)
[ArCOOO-Mo+'] +ArCHO -~ ArCOOH+ [ArCOO-Mo+s]
(4)
[ArCOO-Me+*]+ArCHO -~ ArCOOH+ [ArCO...Me+t]
(5)
[ArCO...Mo +') +O, -+ [ArCOOO-Mo +s]
(6)
ArCOOO'+ArOHO --, ArOOOOH+ArCO
(7)
The ratio of rates of reactions (3)-(7), which depends on catalyst composition and concentration and those of aldehyde, accounts for the inhibition or development of the process. I n fact, on increasing the initial concentration of the cobalt catalyst to 1.37 × 10 -1 mole/l, we also observed an induction period (Table, experiment 12), but oxidation only commenced after the complete transition of cobalt into the trivalent form. SUMMARY
1. I t was established t h a t in non-catalytic oxidation of p-toluic aldehyde at a temperature of 120-200 ° the reaction is self-inhibited with a degree of aldehyde conversion of 80-85%. I t was assumed t h a t p-cresol formed during the thermal conversion of pertoluie acid is the inhibitor. 2. I t was shown t h a t during oxidation of p-toluie aldehyde in the presence of a bromine compound the reaction is non-catalytic. 3. At certain critical concentrations catalysts of liquid-phase oxidation of hydrocarbons function as effective inhibitors in the case ofp-toluic aldehyde. REFERENCES 1. A. M. IVANOV, L. N. lgH~.kl,O and K. A. CHEItVINSKII, ~eftekhimiya 9, 260,
1969 2. N. Ye. C~REPANOVA, K. A. (~[I~ltVINSKII and L. N. KH~KALO, ~him. tekhnol. Resp. mezhved, n.-tekhn, sb. 9, 48, 1967 3. Ya. MOTOTAKE, F. TAIDZO, N. KHIROSI and I. TATSUYA, Koge kagaku dza~i 71, 217, 1968 4. A. M. IVANOV and V. V. TSISAI~UK, Neft,okhlrniya 12, 748, 1972 5. N. G. DIGUROV, V. A. SEDLYAROV, N. N. LEBEDEV and Ys. V. NASTYUKOVA, Nei~kh;miya 9, 552, 1969 6. V. N. JtLI~.K~IA_NDROV,G. S. GOLUBEV, S. S. GITIS, V. V. KHOMIN and N. V. NOVORUSSKAYA, ]~himiya i tekhnol monomerov. Tr. Vses. n..i. i proyektn, in.is taChOmeter 2, 6, 1970 7. V. K. KONDRATOV and N. D. RUS'¥ANOVA, Neftekhlmlya 12, 725, 1972 8. V.N. ALRK~IANDROV,V. V. 1RHOM][N,S. S. GITIS and G. S. GOLUBEV,~ei~Ichimiya 12, 737, 1972 9. Ye. M. K A ~ N. V. NOVORUSSKAYA and V. N. ALEKSAN])ROV, Zh. a, AI;~. khimii 24, 1881, 1969
1~4
M.S. SAZ,U~HOVet al.
10. G. M. GAL'PERN, V. A. IL'INA, P. M. SHUMSKAYA and V. N. ALEgSANDROV, Khlmlya i tekhnol, monomerov. Tr. Vses, n.-i. i proektn, in-t. monomerov 2, 129, 1970 11. A. M. IVANOV, L. N. KHAKALO and K. A. ~CHEItVINSKII, Neftel~hlmiya 8, 589, 1968 12. Ye. M. TOCHINA, L. M. POSTNIKOV and V. Ya. SHLYAPINTOKH, Izv. AN SSSR, Ser. khlm. 71, 1968
OXIDATIVE CHLORINATION OF ETHYLBENZENE AND ISOPROPYLBENZENE* M. S. SAT,A~I~[OV,~V~.~¢~.GUSS]~I~OV,CH. A. CH~,A~IEV and D. K. ABD~LAYEV Stungait Branch of the Institute of Petrochemical Processes Azerb. S.S.R. Academy of Sciences (Received 16 July, 1974)
C ~ o ~ x ~ . derivatives of ethyl and isopropylbenzene are obtained b y alkyiatiou of chlorobenzene in the presence of Friedel-Crafts [1, 2] catalysts b y direct chlorination of ethylbenzene [3-5] and isopropylbenzene [6, 7]. A1Cls, FeCIa, ZnCI~, SnC14 and TiC14 are used as catalysts in chlorination of alkylbenzenes. However, secondary reactions [5, 7] are undesirable in the catalytic process of chlorination. Investigations are being carried out in our laboratory in the field of oxidizing chlorination of alkyl-aromatic hydrocarbons [8]. There is no information in the literature about this problem. • This article is concerned with explaining some relations which govern the preparation of chlorine derivatives of ethyl- and isopropy!benzene b y oxidative chlorination (with a mixture o f hydrochloric acid and hydrogen perox i d e ) . ..... Experiments were carried out in a glass flask provided with a mechanical atirrer, d r o p funnel and a thermometer. Reaction temperature was maintained with an accuracy of ± 0 . 5 °. Commercial hydrochloric acid, ethyl- and isopr0pylbenzene (pure) and a 30% aqueous solution of hydrogen peroxide were used: for the investigation. The flask was filled with these in given proportions. Hydrogen peroxide was added to the reaction mass from a drop funnel. ~ The react:ion mixture was analysed a t equal time intervals b y GLC using an LKhM-7A device with a heat conductivity detector (detector current 90 mA). * Neftekhlrnlya 15, No. 4, 601-605, 1975.