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Catalytic conversions of cyclohexanol and methylcyclohexanols
CATALYTIC CONVERSIONS OF CYCLOHEXANOL AND METHYLCYCLOHEXANOLS * I~. I. SHUIKII~,~ZE. D. TULUPOVX and E. G. OSTAPEI~KO N. D. Zelinskii Institute of Organic Chemistry, U.S.S.R. Academy of Sciences (Received 19 October 1965)
ALKYLCYCLOHEXE:NES can be obtained with high yields catalytic dehydration of corresponding alkylcyclohexanols in the presence of iodine [1], activated clay or alumina [2-3] and during catalytic dehydrochlorination [4-6] of monochloro-derivatives of hydrocarbons of the cyclohexane series. It was noted that these reactions can be complicated b y secondary processes related to the isomerization of a six-membered ring, hydrogen redistribution and polymerization [7]. Methylehlorocyclohexanes in contact with alumina at 400 ° basically produce five-membered cyclanes (64% calculated on the initial chloride [8]). Under these conditions alumina is apparently partially converted into aluminium chloride [9] which promotes the formation of five-membered cyclanes. Under similar conditions, b u t in contact with A1203-3Si02, deposited in a proportion of 20 wt. % on activated carbon, methylchlorocyclohexanes undergo conversions to form dimethyleyelopentenes, the yield of which reaches 55.6%, calculated on the chlorine passed through. It was of interest to elucidate the character of conversions of cyclohexanol and some methylcyclohexanols in the presence of an aluminosilicate catalyst and alumina and compare these data with the results of conversions (under identical condition) of chlorocyclohexane and methylehlorocyclohexanes. It was also important to ascertain the effect of hydrogen chloride on the nature of conversions of methylcyclohexanol and 1-methylcyclohex- 1-ene. An analysis of the reaction products b y gas-liquid chromatography showed that cyclohexanol and methylcyclohexanols are dehydrated on alumina at 400-450 ° to form five- and six-membered cyclenes. Under the same conditions chlorocyclohexane and methylchlorocyclohexanes are dehydroehlorinated to form five-membered cyclanes as main reaction products probably as a result of hydrogen redistribution. The addition to cyclic alcohols of hydrogen chloride in the presence of alumina at 400 ° intensifies the reaction, as a result of which six-membcred cyclancs and corresponding aromatic hydrocarbons are formed. Unlike the reaction taking place in t h e presence of alumina, dehydration * Neftekhimiya 6, No. 5, 764-768, 1966. 246
Catalytic conversions of cyclohexanol and methylcyclohexanols
247
of cyclic alcohols with aluminosilicate deposited on activated carbon, is not accompanied by isomerization of the six-membered ring. Under these conditions the cyclohexane and corresponding aromatic hydrocarbons are the main reaction products. Dilution of cyclic alcohols with hydrogen chloride in this case leads to isomerization of a six-membered ring to a five membered one. Five- and six-membered cyclenes are mainly formed from methylchlorocyclohexanes. Under similar conditions, but in the presence of a catalyst, methylchlorocyclohexane conversion is only accompanied by the separation of elements of hydrogen chloride to form methylcyclohexenes. Consequently, without a catalyst, hydrogen chloride does not promote the isomerization of the six-membered ring. A comparison of the data obtained and the results of 1-methylcyelo-hex-l-ene conversions leads us to the conclusion that under catalytic conditions at 350-450 ° hydrogen redistribution and isomerization of the sixmembered to a five-membered ring largely take place at the moment when water or hydrogen chloride separate. Based on chromatographic data, methylcyclohexanol conversions, under selected conditions, can be shown by schemes I and II.
C,H3
C.H~ AI203
~
C,H3
o
II.
Conversions of cyclohexanol take place according to similar schemes. EXPERtMENTAL
Initial methylcyelohexanols were obtained by hydrogenation of corresponding cresols in an autoclave at 180-200 ° in the presence of a nickel-aluminium catalyst. The pressure of hydrogen fed into the autoclave was 100-120 atm. The eatalysates obtained were treated with 10~/o sodium hydroxide solution. After drying over anhydrous sodium sulphate, each of the alcohols obtained was distilled in a column with efficiency of 24 theoretical plates at atmospheric and reduced pressure. Their properties are shown in Table 1. Chlorocyclohexane
248
N . I . SHUIKII~ eta/. T A B L E 1. P R O P E R T I E S OF I N I T I A L METHYLCYCLOHEXANOLS
Alcohol 1-Methylcyclohexan-2-ol 1-Methylcyclohexan-3-ol 1-Methylcyclohexan-4-ol
B.p., °C (mmHg)
n~°
d~
75"5-76(25) 165-166.5(760)
1-4635
0.9315
83-84(25) 170-171(727)
1.4580
0.9185
83.5-85(25) 171-172(744)
1.4582
0-9195
a n d m e t h y l c h l o r o c y c l o h e x a n e s are described in references [4, 5]. To i n v e s t i g a t e t h e conversions o f these s u b s t a n c e s , t h e following were u s e d as catalysts: a l u m i n a A I , calcined in a muffle f u r n a c e a t 500 ° for 2 h o u r s a n d a c t i v a t e d charcoal c o n t a i n i n g 20~/o aluminosilicate. F o r t h e p r o p o r t i o n of t h e l a t t e r , a c t i v a t e d charcoal was s a t u r a t e d w i t h a l u m i n i u m n i t r a t e solution, t h e n w i t h s o d i u m silicate solution, rinsed w i t h w a t e r a t r o o m t e m p e r a t u r e until N 0 a was r e m o v e d a n d dried a t 180-200 °. T h e e x p e r i m e n t s were carried o u t in a conventional continuous laboratory apparatus. In each experiment the apparent c a t a l y s t v o l u m e w a s 100 ml, t h e a m o u n t of initial alcohol 30 ml. T h e liquid p r o d u c t s f r o m t h e c a t a l y t i c conversions of m e t h y l c y c l o h e x a n o l s were s e p a r a t e d
T A B L E 2. CATALYTIC CONVERSIONS OF CYCLOHEXANOL AND CHLOROCYCLOHEXANE
Space velocity of feed 0.6 hour -~ Composition of 70-112 ° boiling fractions % stiochiometric =
o
Initial substance
Catalyst
? =
o
= ¢9
~J O
Cyclohexanol Chloroeyclohexane Cyclohexanol Same Chlorocyelohexane
Al,08
450 450
20~o A1,O, •3SiO, on carbon Same
450 400 350 450
O
82.0 80.0
'
O
22.5 56.5 51. 3"0 --
3.0 - - 0
920 4.52.01.
94.0 94"0 84.6
18.0 Tra COS
0.5
6.~ 90"0
0.5 42.C 1.0 55.0] 2.0 38.£ 0 79'0 8.£ 12.7 0.5 3L0 5~8 4.0
I
5~ 0
o
t~
~.~
g
~
r.
0 0
0 0
0 0
0 0
~ 0
0 0
~ 0
tempera~ure, ~u
x 1el(1 oI tile eataly-
0
sate fraction w i t h a boiling range of 70-112 °, % theor.
< t~
1,3-dimethylcyclopent- 1ene
©
l
2,4-dimethylc y c l o p e n t - 1-
]l&~
ene D
0
o
D
2,3-dimethylcyclopent- 1ene
1,2-dimethylc y c l o p e n t - 1-
I I ~ l L [ I :e
eno
t
2-aad 0
3-ethylcyclo-
pent-l-enes 2-and 3 -methylcyclo hex- 1-enes 1-methyl-
cyclohex- 1ene
0 0 t~
0
t~
toluene
methylcyclohexano
] l ~ l l l l
)T'5
,1 -ctlmetnyl:yclopentane
SIOU~XOqOIOAOIAq~om pUU [OU~XOqOIOAOJo SUO!SZOAUO0Ot.$A[~ o
250
1~. I. SnvlaI~ et al.
from water, dried and distilled. Hydrocarbon fractions evaporating below 112 ° (yield 82-97 % stoichiometrie) were analysed by gas-liquid chromatography in an apparatus with a hydrogen-flame detector. A copper tube of 5 m length and 5 m m internal diameter was used as column. Tricresyl phosphate and sunflower oil (20% of the weight of the tarrier), applied on diatomite of grain size of 0-5-0.25 m m were the stationary liquid phases. The gas-carrier, hydrogen, was passed through at a rate of 60 ml/min. C6 hydrocarbon mixtures were analysed at 60 °, C7 hydrocarbon mixtures at 90 °. The components were identified by means of reference hydrocarbons [10]. Composition of the catalysates obtained are shown in Table 2 and 3. Table 2 indicates that at 450 ° and on using alumina as catalyst, the conversion products of cyclohexanol contain 79% methylcyclopentenes, 18% cyclohexene and small amounts of cyelohexane and benzene. The conversion products of chlorocyclohexane, obtained under the same conditions, contained 90% methylcyclopentane, 6.5% benzene and 3% 1-methylcyclopent-l-ane. On aluminosilicate (20%) deposited on activated charcoal, 86.8% methyleyclopentenes are formed from chlorocyelohexane and 51.0% cyclohexane, 42% benzene and only 6.5% methylcyclopentenes are formed from cyclohexanol. The data in Table 3 indicate that, at 450 ° in contact with alumina, methylcyelohexanols are converted to isomeric dimethylcyclopentenes and methylcyclohexenes, with contents in the mixture of 85.7 and 14.3%, respectively. Methylchlorocyclohexanes are basically converted to dimethylcyclopentanes (84.4% in a boiling point fraction of 70-112°). The main conversion products of methylcyclohexanols in contact with aluminosilicate are methylcyclohexane and toluene. Five- and six-membered cyclenes were obtained from methylchlorocyclohexanes. Under the conditions adopted the nature of 1,2- and 1,4methycyclohexanol conversions is similar to the conversions of 1,3-methylcyclohexanol. SUMMARY
1. Investigations were made of catalytic conversions of cyclohexanol, methylcyclohexanols, chlorocyelohexane and methylchlorocyclohexanes in contact with alumina and aluminosilicate (20% Al~Oa'SiO2) on activated charcoal at 400-450 ° . 2. In the presence of alumina at 450 ° methylcyclohexanols were converted to five- and six-membered cyclenes and chloroeyclohexane and methyl-ehlorohexanes into five-membered cyclanes. 3. I n contact with alumino-silicate (20%) on activated charcoal dehydration of cyclic alcohols is accompanied by formation of six-membered cyclanes and corresponding aromatic hydrocarbons. Chlorocyclohexane and methylchlorocyclohexanes undergo dehydrochlorination into five- and six-membcred cyclenes. Translated by E. SEMERE
Catalytic conversions of cyelohexanol and methylcyclohexanols
251
R~FERENCES 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
W. A. MOSER, J. Amer. Chem. Soc. 62, 552, 1940 Brit. P a t e n t 756751, 1956; RefZhKhim., 27628, :No. 7, 1960 U.S.A. P a t e n t 3016409, 1962, Ref. Zh. Khim., 11:N78P, 1963 N. I. SHUIKIN, Ye. D. TULUPOVA, E. G. OSTAPENKO, :Neftekhimiya 3, :No. 1, 60, 1963 (Not translated in Petroleum Chemistry U.S.S.R.) N. I. SHUIKIN, Ye. D. TULUPOVA, Z. P. POLYAKOVA a n d D. A. KONDRAT'EV, Izv. Akad. N a u k SSSR., Otd. khim. n., 858, 1961 N. I. SHUIKIN, Ye. D. TULUPOVA a n d E. G. OSTAPENKO, Neftekhimiya 4, No. 6, 876, 1964 (:Not translated in Petroleum Chemistry U.S.S.R.) N. I. SHUIKIN, L. A. ERIVANSKAYA, Neftekhimiya 4, :No.3, 431, 1964 (Not translated in Petroleum Chemistry U.S.S.R.) N. I. SHUIKIN, Ye. D. TULUPOVA a n d E. G. OSTAPENKO, :Neftekhimiya 3, No. 2, 203, 1963 (Not translated in Petroleum Chemistry U.S.S.R.) AI. A. PETROV, K a t a l i c h e s k a y a isomerizatsiya uglevodorodov (Catalytic Isomerization of Hydrocarbons). Izd-vo Akad. N a u k SSSR., Moscow, 1960 N. I. SHUIKIN, Ye. D. TULUPOVA and E. G. OSTAPENKO, Neftekhimiya 3, ~ o . 2, 202, 1963 (Not translated in Petroleum Chemistry U.S.S.R.)
ALKYLCYCLOHEXE:NES can be obtained with high yields catalytic dehydration of corresponding alkylcyclohexanols in the presence of iodine [1], activated clay or alumina [2-3] and during catalytic dehydrochlorination [4-6] of monochloro-derivatives of hydrocarbons of the cyclohexane series. It was noted that these reactions can be complicated b y secondary processes related to the isomerization of a six-membered ring, hydrogen redistribution and polymerization [7]. Methylehlorocyclohexanes in contact with alumina at 400 ° basically produce five-membered cyclanes (64% calculated on the initial chloride [8]). Under these conditions alumina is apparently partially converted into aluminium chloride [9] which promotes the formation of five-membered cyclanes. Under similar conditions, b u t in contact with A1203-3Si02, deposited in a proportion of 20 wt. % on activated carbon, methylchlorocyclohexanes undergo conversions to form dimethyleyelopentenes, the yield of which reaches 55.6%, calculated on the chlorine passed through. It was of interest to elucidate the character of conversions of cyclohexanol and some methylcyclohexanols in the presence of an aluminosilicate catalyst and alumina and compare these data with the results of conversions (under identical condition) of chlorocyclohexane and methylehlorocyclohexanes. It was also important to ascertain the effect of hydrogen chloride on the nature of conversions of methylcyclohexanol and 1-methylcyclohex- 1-ene. An analysis of the reaction products b y gas-liquid chromatography showed that cyclohexanol and methylcyclohexanols are dehydrated on alumina at 400-450 ° to form five- and six-membered cyclenes. Under the same conditions chlorocyclohexane and methylchlorocyclohexanes are dehydroehlorinated to form five-membered cyclanes as main reaction products probably as a result of hydrogen redistribution. The addition to cyclic alcohols of hydrogen chloride in the presence of alumina at 400 ° intensifies the reaction, as a result of which six-membcred cyclancs and corresponding aromatic hydrocarbons are formed. Unlike the reaction taking place in t h e presence of alumina, dehydration * Neftekhimiya 6, No. 5, 764-768, 1966. 246
Catalytic conversions of cyclohexanol and methylcyclohexanols
247
of cyclic alcohols with aluminosilicate deposited on activated carbon, is not accompanied by isomerization of the six-membered ring. Under these conditions the cyclohexane and corresponding aromatic hydrocarbons are the main reaction products. Dilution of cyclic alcohols with hydrogen chloride in this case leads to isomerization of a six-membered ring to a five membered one. Five- and six-membered cyclenes are mainly formed from methylchlorocyclohexanes. Under similar conditions, but in the presence of a catalyst, methylchlorocyclohexane conversion is only accompanied by the separation of elements of hydrogen chloride to form methylcyclohexenes. Consequently, without a catalyst, hydrogen chloride does not promote the isomerization of the six-membered ring. A comparison of the data obtained and the results of 1-methylcyelo-hex-l-ene conversions leads us to the conclusion that under catalytic conditions at 350-450 ° hydrogen redistribution and isomerization of the sixmembered to a five-membered ring largely take place at the moment when water or hydrogen chloride separate. Based on chromatographic data, methylcyclohexanol conversions, under selected conditions, can be shown by schemes I and II.
C,H3
C.H~ AI203
~
C,H3
o
II.
Conversions of cyclohexanol take place according to similar schemes. EXPERtMENTAL
Initial methylcyelohexanols were obtained by hydrogenation of corresponding cresols in an autoclave at 180-200 ° in the presence of a nickel-aluminium catalyst. The pressure of hydrogen fed into the autoclave was 100-120 atm. The eatalysates obtained were treated with 10~/o sodium hydroxide solution. After drying over anhydrous sodium sulphate, each of the alcohols obtained was distilled in a column with efficiency of 24 theoretical plates at atmospheric and reduced pressure. Their properties are shown in Table 1. Chlorocyclohexane
248
N . I . SHUIKII~ eta/. T A B L E 1. P R O P E R T I E S OF I N I T I A L METHYLCYCLOHEXANOLS
Alcohol 1-Methylcyclohexan-2-ol 1-Methylcyclohexan-3-ol 1-Methylcyclohexan-4-ol
B.p., °C (mmHg)
n~°
d~
75"5-76(25) 165-166.5(760)
1-4635
0.9315
83-84(25) 170-171(727)
1.4580
0.9185
83.5-85(25) 171-172(744)
1.4582
0-9195
a n d m e t h y l c h l o r o c y c l o h e x a n e s are described in references [4, 5]. To i n v e s t i g a t e t h e conversions o f these s u b s t a n c e s , t h e following were u s e d as catalysts: a l u m i n a A I , calcined in a muffle f u r n a c e a t 500 ° for 2 h o u r s a n d a c t i v a t e d charcoal c o n t a i n i n g 20~/o aluminosilicate. F o r t h e p r o p o r t i o n of t h e l a t t e r , a c t i v a t e d charcoal was s a t u r a t e d w i t h a l u m i n i u m n i t r a t e solution, t h e n w i t h s o d i u m silicate solution, rinsed w i t h w a t e r a t r o o m t e m p e r a t u r e until N 0 a was r e m o v e d a n d dried a t 180-200 °. T h e e x p e r i m e n t s were carried o u t in a conventional continuous laboratory apparatus. In each experiment the apparent c a t a l y s t v o l u m e w a s 100 ml, t h e a m o u n t of initial alcohol 30 ml. T h e liquid p r o d u c t s f r o m t h e c a t a l y t i c conversions of m e t h y l c y c l o h e x a n o l s were s e p a r a t e d
T A B L E 2. CATALYTIC CONVERSIONS OF CYCLOHEXANOL AND CHLOROCYCLOHEXANE
Space velocity of feed 0.6 hour -~ Composition of 70-112 ° boiling fractions % stiochiometric =
o
Initial substance
Catalyst
? =
o
= ¢9
~J O
Cyclohexanol Chloroeyclohexane Cyclohexanol Same Chlorocyelohexane
Al,08
450 450
20~o A1,O, •3SiO, on carbon Same
450 400 350 450
O
82.0 80.0
'
O
22.5 56.5 51. 3"0 --
3.0 - - 0
920 4.52.01.
94.0 94"0 84.6
18.0 Tra COS
0.5
6.~ 90"0
0.5 42.C 1.0 55.0] 2.0 38.£ 0 79'0 8.£ 12.7 0.5 3L0 5~8 4.0
I
5~ 0
o
t~
~.~
g
~
r.
0 0
0 0
0 0
0 0
~ 0
0 0
~ 0
tempera~ure, ~u
x 1el(1 oI tile eataly-
0
sate fraction w i t h a boiling range of 70-112 °, % theor.
< t~
1,3-dimethylcyclopent- 1ene
©
l
2,4-dimethylc y c l o p e n t - 1-
]l&~
ene D
0
o
D
2,3-dimethylcyclopent- 1ene
1,2-dimethylc y c l o p e n t - 1-
I I ~ l L [ I :e
eno
t
2-aad 0
3-ethylcyclo-
pent-l-enes 2-and 3 -methylcyclo hex- 1-enes 1-methyl-
cyclohex- 1ene
0 0 t~
0
t~
toluene
methylcyclohexano
] l ~ l l l l
)T'5
,1 -ctlmetnyl:yclopentane
SIOU~XOqOIOAOIAq~om pUU [OU~XOqOIOAOJo SUO!SZOAUO0Ot.$A[~ o
250
1~. I. SnvlaI~ et al.
from water, dried and distilled. Hydrocarbon fractions evaporating below 112 ° (yield 82-97 % stoichiometrie) were analysed by gas-liquid chromatography in an apparatus with a hydrogen-flame detector. A copper tube of 5 m length and 5 m m internal diameter was used as column. Tricresyl phosphate and sunflower oil (20% of the weight of the tarrier), applied on diatomite of grain size of 0-5-0.25 m m were the stationary liquid phases. The gas-carrier, hydrogen, was passed through at a rate of 60 ml/min. C6 hydrocarbon mixtures were analysed at 60 °, C7 hydrocarbon mixtures at 90 °. The components were identified by means of reference hydrocarbons [10]. Composition of the catalysates obtained are shown in Table 2 and 3. Table 2 indicates that at 450 ° and on using alumina as catalyst, the conversion products of cyclohexanol contain 79% methylcyclopentenes, 18% cyclohexene and small amounts of cyelohexane and benzene. The conversion products of chlorocyclohexane, obtained under the same conditions, contained 90% methylcyclopentane, 6.5% benzene and 3% 1-methylcyclopent-l-ane. On aluminosilicate (20%) deposited on activated charcoal, 86.8% methyleyclopentenes are formed from chlorocyelohexane and 51.0% cyclohexane, 42% benzene and only 6.5% methylcyclopentenes are formed from cyclohexanol. The data in Table 3 indicate that, at 450 ° in contact with alumina, methylcyelohexanols are converted to isomeric dimethylcyclopentenes and methylcyclohexenes, with contents in the mixture of 85.7 and 14.3%, respectively. Methylchlorocyclohexanes are basically converted to dimethylcyclopentanes (84.4% in a boiling point fraction of 70-112°). The main conversion products of methylcyclohexanols in contact with aluminosilicate are methylcyclohexane and toluene. Five- and six-membered cyclenes were obtained from methylchlorocyclohexanes. Under the conditions adopted the nature of 1,2- and 1,4methycyclohexanol conversions is similar to the conversions of 1,3-methylcyclohexanol. SUMMARY
1. Investigations were made of catalytic conversions of cyclohexanol, methylcyclohexanols, chlorocyelohexane and methylchlorocyclohexanes in contact with alumina and aluminosilicate (20% Al~Oa'SiO2) on activated charcoal at 400-450 ° . 2. In the presence of alumina at 450 ° methylcyclohexanols were converted to five- and six-membered cyclenes and chloroeyclohexane and methyl-ehlorohexanes into five-membered cyclanes. 3. I n contact with alumino-silicate (20%) on activated charcoal dehydration of cyclic alcohols is accompanied by formation of six-membered cyclanes and corresponding aromatic hydrocarbons. Chlorocyclohexane and methylchlorocyclohexanes undergo dehydrochlorination into five- and six-membcred cyclenes. Translated by E. SEMERE
Catalytic conversions of cyelohexanol and methylcyclohexanols
251
R~FERENCES 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
W. A. MOSER, J. Amer. Chem. Soc. 62, 552, 1940 Brit. P a t e n t 756751, 1956; RefZhKhim., 27628, :No. 7, 1960 U.S.A. P a t e n t 3016409, 1962, Ref. Zh. Khim., 11:N78P, 1963 N. I. SHUIKIN, Ye. D. TULUPOVA, E. G. OSTAPENKO, :Neftekhimiya 3, :No. 1, 60, 1963 (Not translated in Petroleum Chemistry U.S.S.R.) N. I. SHUIKIN, Ye. D. TULUPOVA, Z. P. POLYAKOVA a n d D. A. KONDRAT'EV, Izv. Akad. N a u k SSSR., Otd. khim. n., 858, 1961 N. I. SHUIKIN, Ye. D. TULUPOVA a n d E. G. OSTAPENKO, Neftekhimiya 4, No. 6, 876, 1964 (:Not translated in Petroleum Chemistry U.S.S.R.) N. I. SHUIKIN, L. A. ERIVANSKAYA, Neftekhimiya 4, :No.3, 431, 1964 (Not translated in Petroleum Chemistry U.S.S.R.) N. I. SHUIKIN, Ye. D. TULUPOVA a n d E. G. OSTAPENKO, :Neftekhimiya 3, No. 2, 203, 1963 (Not translated in Petroleum Chemistry U.S.S.R.) AI. A. PETROV, K a t a l i c h e s k a y a isomerizatsiya uglevodorodov (Catalytic Isomerization of Hydrocarbons). Izd-vo Akad. N a u k SSSR., Moscow, 1960 N. I. SHUIKIN, Ye. D. TULUPOVA and E. G. OSTAPENKO, Neftekhimiya 3, ~ o . 2, 202, 1963 (Not translated in Petroleum Chemistry U.S.S.R.)