516 Liu et al.
Asian J. Chem.
TABLE-4
a
COMPARISON OF THE OTHER AROMATICS NITRATION IN DIFFERENT REACTORS
b
Reaction
time
Conversion
(%)
Selectivity
(%)
Product distribution (%)
Substrate
Reactor
o/p ratio
ortho
meta
para
A
B
7200 s
48 s
53.8
60.1
99.1
> 99.5
–
–
–
–
A
B
7200 s
48 s
72.2
78
98.9
99.3
45.8
45.4
4.9
5.3
49.3
51.3
0.93
0.88
A
B
7200 s
42 s
73.9
91.4
90.7
94.6
26.4
24.8
6.9
6.8
66.7
68.4
0.40
0.36
A
B
7200 s
48 s
74.5
80.3
98.7
> 99.5
15.3
14.3
10.1
9.8
74.6
75.9
0.20
0.19
F
A
B
7200 s
48 s
55.8
59.6
99.1
> 99.5
16.6
17.1
0.3
–
84.1
82.9
0.20
0.21
Cl
A
B
7200 s
48 s
51.9
58.4
99.1
> 99.5
33.8
39.2
0.4
–
65.8
60.8
0.51
0.65
Br
A
B
7200 s
48 s
42.3
48.5
99.3
> 99.5
34.3
38.9
0.4
–
65.3
61.1
0.52
0.64
a
Reaction conditions: toluene velocity 1 mL/min, n(aromatics):n(N O )=1:1.2, CH Cl as solvent, bath temperature 30 °C, continuous flow, no
2
5
2
2
b
catalyst; A = batch reactor, V= 100 mL; B = microglass reactor, V= 1.326 mL
TABLE-3
ACKNOWLEDGEMENTS
EFFECT OF SOLVENT IN TOLUENE NITRATION
WITH PEG400-DAIL IN THE MICROREACTOR
The authors are grateful for the Natural Science Foundation
of Jiangsu Province (No. BK2011697) and Independent Scientific
Research Special Plan of NJUST (No. 2011YBXM06).
Conversion Selectivity
Product isomers (%)
ortho meta para ratio
o/p
Solvent
CCl4
(%)
(%)
72.2
95.5
95.8
96.6
99.0
> 99.5
> 99.5
99.4
99.3
99.0
51.3
51.5
51.6
52.6
53.0
1.7
1.7
2.0
2.1
2.3
47.0
46.8
46.4
45.3
44.7
1.09
1.10
1.11
1.16
1.18
REFERENCES
CH Cl2
2
CHCl3
1
.
H.W. Yang, X.F. Qi, L. Wen, C. Lu and G. Cheng, Ind. Eng. Chem.
Res., 50, 11440 (2011).
2. S.J. Wang, S.J. Jiang and J. Nie, Adv. Synth. Catal., 351, 1939 (2009).
3. G.A. Olah, S.J. Kuhn, S.H. Flood and J.C. Evans, J. Am. Chem. Soc.,
84, 3687 (1962).
CH CN
3
3
CH NO2
Reaction conditions: Toluene velocity 1 mL/min, reaction time = 48 s,
n(toluene):n(N O ) = 1:2, bath temperature 30 °C, continuous flow,
2
5
PEG400-DAIL (catalyst’s amount 5.0 % mol (mole ratio to toluene)).
added into acid phase, ignored the change of volume.
4. A.V. Aksenov, A.S. Lyakhovnenko, T.S. Perlova and I.V. Aksenova,
Chem. Heterocycl. Compd., 47, 245 (2011).
5
6
7
8
9
.
.
.
.
.
K. Smith, S. Liu and G.A. El-Hiti, Ind. Eng. Chem. Res., 44, 8611
2005).
M.E. Kurz, L.T. Yang, E.P. Zahora and R.C. Adams, J. Org. Chem., 38,
271 (1973).
S. Gong, L. Liu, J. Zhang and Q. Cui, Process Saf. Environ. Prot., 92,
577 (2013).
J. Antes, D. Boskovic, H. Krause, S. Loebbecke, N. Lutz, T. Tuercke
and W. Schweikert, Trans. IChemE, 81, 760 (2003).
J.M. Zaldivar, C. Barcons, H. Hernandez, E. Molga and T.J. Snee, Chem.
Eng. Sci., 47, 2517 (1992).
(
Comparison of the other aromatics nitration in diffe-
rent reactors: On the basis of toluene, with N
2
O for nitrating
5
2
agent, we compared the other aromatics nitration results in
different reactors in the same mole ratio and reaction tempe-
rature, as shown in Table-4.
The procedure was repeated six times and the results
indicated that PEG400-DAIL could be recycled without the
apparent loss of catalytic activity after six times of recycling.
10. R. Halder, A. Lawal and R. Damavarapu, Catal. Today, 125, 74 (2007).
1
1. K. Jahnisch, V. Hessel, H. Lowe and M. Baerns, Angew. Chem. Int.
Ed., 43, 406 (2004).
2. R.W. Millar and S.P. Philbin, Tetrahedron, 53, 4371 (1997).
Conclusion
1
The PEG400-DAIL was used as homogeneous, recyclable
catalysts for continuous nitration in a special microglass
reactor. Under the same conditions, the conversion of alkyl-
benzenes and halogenated-benzenes were increased about 15 %
and 10 % versus batch reactor and the yield of mononitration
product significantly improved, meanwhile the reaction time
was drastically shortened to 1/120 of the conventional reactor.
Further systematic work towards nitrating via a continuous
flow microreactor is in progress.
13. R.R. Bak and A.J. Smallridge, Tetrahedron Lett., 42, 6767 (2001).
1
4. K. Qiao, H. Hagiwara and C.J. Yokoyama, J. Mol. Catal. Chem., 246,
5 (2006).
6
1
1
5. K. Qiao and C. Yokoyama, Chem. Lett., 33, 808 (2004).
6. G. Cheng, X. Duan, X. Qi and C. Lu, Catal. Commun., 10, 201 (2008).
17. P.-C. Wang and M. Lu, Tetrahedron Lett., 52, 1452 (2011).
1
8. D. Fang, Q.R. Shi, J. Cheng, K. Gong and Z.-L. Liu, J. Appl. Catal. A,
45, 158 (2008).
9. K.-Q. Zhao, P. Hu, H.-B. Xu and L.-F. Zhang, Chin. Chem. Lett., 20,
79 (2009).
20. X.-F. Chao, B.-D. Li and M. Wang, Chin. Chem. Lett., 25, 4 (2014).
3
1
4