Binary oxide systems in catalytic synthesis of 2-methylpyrazine from 1,2-propylene glycol and ethylenediamine

Article abstract of DOI:10.1023/A:1015579715128

A series of binary catalysts based on oxides of zinc and variable-valence metals were tested in synthesis of 2-methylpyrazine by catalytic dehydrocyclization of 1,2-propylene glycol with ethylenediamine.

Full text of DOI:10.1023/A:1015579715128

Russian Journal of Applied Chemistry, Vol. 74, No. 12, 2001, pp. 2125 2127. Translated from Zhurnal Prikladnoi Khimii, Vol. 74, No. 12, 2001,
pp. 2065 2067.
Original Russian Text Copyright
2001 by Balpanov, Krichevskii, Kagarlitskii.
BRIEF
COMMUNICATIONS
Binary Oxide Systems in Catalytic Synthesis of 2-Methylpyrazine
from 1,2-Propylene Glycol and Ethylenediamine
D. S. Balpanov, L. A. Krichevskii, and A. D. Kagarlitskii
Institute of Phytochemistry, Ministry of Education and Science of the Kazakhstan Republic, Karaganda, Kazakhstan
Buketov State University, Karaganda, Kazakhstan
Received August 16, 2001
Abstract A series of binary catalysts based on oxides of zinc and variable-valence metals were tested in
synthesis of 2-methylpyrazine by catalytic dehydrocyclization of 1,2-propylene glycol with ethylenediamine.
The growing incidence of tubercular diseases calls
for improving the synthesis processes and increasing the
production of tuberculostatic means. One of the most
Its active agent, which is also the starting compound
for preparing low-toxic bacteriostatics [1], is pyrazine-
2-carboxamide, prepared by oxidative ammonolysis of
important antitubercular preparations is Pyrazinamide. 2-methylpyrazine (MP) [2].
N
N
N
N
N
N
CH3
CN
CONH2
NH3, O2, , Cat.
H2O
By now, fairly selective catalysts have been devel-
oped for oxidative ammonolysis of MP, allowing
preparation, depending on reaction conditions, of
either 2-cyanopyrazine [3] or 2-pyrazinamide [4] in
yields of 80% and higher; however, there are no com-
mercially acceptable procedures for synthesis of the
starting compound.
based on oxides of Zn [7 9], Cu, or Cr(III) [10]; in
their presence, the yield of MP reaches 60 70%. The
best results are obtained with catalysts prepared by
mixing the components to a pasty state, with subse-
quent extrusion and drying [8].
In this study, we tested MoO3-modified zinc oxide
catalysts prepared by such a procedure. The depen-
dence of the MP yield on the catalyst composition
and reaction temperature is illustrated by Fig. 1. We
found that the catalyst containing ZnO and MoO3 in
1 : 0.3 molar ratio ensures a yield of the target prod-
uct as high as 75 80% in the temperature range
420 460 C.
The existing routes to MP, involving synthesis and
subsequent dehydrogenation of 2-methylpiperazine [5]
or reaction of propylene oxide with ethylenediamine
at elevated pressure [6], are of no promise for com-
mercial production of MP.
One of efficient routes to MP can be catalytic de-
hydrocyclization of ethylenediamine with 1,2-propyl-
ene glycol.
However, we found that the catalysts prepared
by extrusion are rapidly coked and require frequent
regeneration, which results in the loss of mechan-
ical strength and, finally, in decreased yield of the
target product. The service life of such catalysts does
not exceed 10 h.
HO
CH CH3
CH2
HO
NH2
CH2
N
N
CH3
+
CH2
NH2
3H2, 2H2O
To prolong the service life of the zinc molybde-
num catalysts and enhance their mechanical strength,
the catalysts were prepared by pelletizing with sub-
At present, the most frequently used cyclizing and
dehydrogenating catalysts for this reaction are those
1070-4272/01/7412-2125 $25.00 2001 MAIK Nauka/Interperiodica

2126
BALPANOV et al.
Data in the table also show that we failed to im-
prove the properties of zinc oxide catalysts by their
modification with vanadium and tungsten oxides.
The results obtained in dehydrocyclization of 1,2-
propylene glycol with ethylenediamine in the presence
of ZnO MoO3 catalyst of the composition ZnO :
MoO3 = 1.0 : 0.3, prepared by granulation, deserve
attention. The service life of this catalyst between
regenerations, 20 h, is twice that of the catalyst pre-
pared by extrusion. It should be noted that the opti-
mal selectivity of this catalyst noticeably depends
on the grain size (Fig. 2).
Fig. 1. MP yield A vs. temperature T. Catalyst ZnO MoO
3
prepared by extrusion; ZnO : MoO ratio: (1) 1 : 0.2,
3
(2) 1 : 0.3, and (3) 1 : 0.4.
EXPERIMENTAL
Extrudates were prepared according to [11]. To
obtain catalysts as pellets, the oxides were thorough-
ly mixed to uniform state and pressed at 100 atm
(catalyst with WO3, at 500 atm) in plunger dies with
cell size of 4 4 mm. Pellets were dried at 105 C
for 2 h, promoted with 1% MnSO4 and 3% H3PO4
solutions [11], and again dried under the same con-
ditions, with subsequent calcination in a muffle fur-
nace at 650 C for 1 h.
Fig. 2. Effect of the granulometric composition of the
1 : 0.3 ZnO MoO catalyst on the MP yield A at 460 C.
3
( ) Time of catalyst operation. Grain size, mm: (1) 0 1,
(2) 1 2, and (3) 2 3.
For granulation, we used ZnO and MoO3 with
particle size of 10 40 and 40 60 m, respectively.
The oxides were mixed to uniform state and pellet-
ized in a cup granulator by spraying a 5% NaOH so-
lution in amount of 5 20% of the mixture weight.
The resulting pellets were dried successively at 50
80 (2 h) and 100 150 C (2 h). The dried grains
were sieved to obtain 0 1-, 1 2-, and 2 3-mm frac-
tions and promoted similarly to the pellets prepared
by pressing. Then the grains were dried for 2 h at
250 C.
sequent calcination. The results obtained with pelle-
tized catalysts were similar to those obtained with the
catalysts prepared by extrusion (see table). Although
the mechanical strength increased considerably, the
service life between regenerations decreased to 6 h,
probably owing to a decrease in the specific surface
area in the course of pelletizing.
MP yield at various compositions of binary catalysts. Feed
1
space velocity 120 h
The catalyst (extrudates, pellets, or grains) was
charged in an amount of 150 cm3 into a straight-flow
reactor with a stainless steel tube (400 mm long,
20 mm i.d.), into which an equimolar mixture of
ethylenediamine and 1,2-propylene glycol, diluted
with 40 vol % water and preheated in a steam heater
MP yield, %, at indicated temperature, C
Catalyst*
380 400 420 440 460
480
ZnO : MoO3:
1 : 0.2
23
58
53
27
63
57
34
74
62
42
82
55
37
79
50
30
67
44
1 : 0.3
1 : 0.4
1
to 280 300 C, was fed at a space velocity of 120 h .
The reaction temperature was adjusted within 420
470 C; the reaction products were cooled in the trap-
ping system.
ZnO : V2O5:
1 : 0.2
1 : 0.3
1 : 0.4
22
30
27
31
46
39
40
58
49
45
50
47
37
43
38
31
35
34
MP was isolated from the reaction mixture as an
azeotrope with water {bp 97 C (737 mm Hg), MP
content 45% [12]}, from which the target product was
recovered by extraction with chloroform or diethyl
ether.
ZnO : WO3:
1 : 0.1
1 : 0.2
29
27
38
33
42
38
51
43
55
52
50
50
*
Molar ratio of the components is given.
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 74 No. 12 2001

BINARY OXIDE SYSTEMS IN CATALYTIC SYNTHESIS OF 2-METHYLPYRAZINE
2127
The reaction course was monitored by GLC
(Chrom-5 chromatograph, flame-ionization detector,
2500 3-mm glass column, stationary phase 5% SE-
30 on Chromaton N-AW-HMDS, column temperature
100 C, vaporizer temperature 180 C, detector temper-
2. Krichevskii, L.A. and Kagarlitskii, A.D., Abstracts of
Papers, Konferentsiya Prikladnye aspekty sovershen-
stvovaniya khimicheskikh tekhnologii i materialov
(Conf. Applied Aspects of Improvement of Chemical
Technologies and Materials ), Biisk, 1998, part 1,
pp. 27 31.
1
ature 190 C, carrier gas argon, flow rate 20 ml min ).
3. FRG Patent Appl. 3107756.
4. Kagarlitskii, A.D. and Krichevskii, L.A., in Novosti
The constants of the isolated MP after distillation
(bp 135 C, n2D0 1.4967, d240 1.030) were consistent
with published data [13].
organicheskoi khimii
i uglekhimii Tsentral’nogo
Kazakhstana (News of Organic Chemistry and Coal
Chemistry of Central Kazakhstan), Karaganda, 1983,
pp. 115 117.
The mass spectrum of MP, taken on an MKh-1300
spectrometer (m/z 94, 67, 26, 39, 40, 53, 38, 42, 28,
41) confirms the structure of the synthesized MP [14].
5. Isagulyants, G.V., Gitis, K.M., and Myasnikov, V.A.,
Izv. Akad. Nauk SSSR, Ser. Khim., 1990, no. 7,
pp. 1483 1486.
CONCLUSIONS
6. US Patent 4097478.
(1) New zinc oxide catalysts modified with Mo,
V, and W oxides were developed and tested in syn-
thesis of 2-methylpyrazine from 1,2-propylene glycol
and ethylenediamine.
7. Kushner, S., J. Am. Chem. Soc., 1952, vol. 74, no. 4,
pp. 3617 3622.
8. Forni, L., J. Catal., 1988, vol. 111, no. 1, pp. 199 209.
9. Gazaliev, A.M., Sim, E.P., Matveev, Yu.A., et al.,
Izv. Akad. Nauk Kaz. SSR, Ser. Khim., 1984, no. 5,
pp. 78 80.
(2) The selectivity of the mixed oxide catalyst
ZnO MoO3 (molar ratio 1 : 0.3) with respect to
2-methylpyrazine is as high as 75 82% under the
optimal conditions (420 460 C).
10. Shimizu, Sh., J. Catal. Soc. Jpn., 1993, vol. 35, no. 1,
pp. 21 29.
11. JPN Patent Appl. 54-132588.
(3) The Zn Mo O catalyst produced by granula-
tion has a considerably longer service life between re-
generations than the catalysts prepared by pelletizing
and extrusion.
12. Ogorodnikov, S.K., Lestova, T.M., and Kagan, V.B.,
Azeotropnye smesi: Spravochnik (Azeotropic Mix-
tures: Handbook), Leningrad: Khimiya, 1971, p. 72.
13. Kitchen, L.J. and Hanson, E.S., J. Am. Chem. Soc.,
1951, vol. 73, no. 2, p. 1838.
REFERENCES
14. Katalog sokrashchennykh mass-spektrov (Catalog of
Concise Mass Spectra), Novosibirsk: Nauka, 1981,
p. 31.
1. Vontor, T., Palat, K., and Odlerova, Z., Cs. Farm.,
1987, vol. 36, no. 6, pp. 277 280.
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 74 No. 12 2001