Month 2014
Effect of Alkali Treatment of HY Zeolite on Continuous Synthesis of Triacetonamine
Catalyst characterization. The XRD patterns were collected
on a Rigaku D/max 2500 (Rigaku Corporation, Japan) using a Cu
Kα X-ray source (40KV, 100mA) in the range of 5–90°.
N2 adsorption and desorption experiments were performed in
liquid nitrogen using a NOVA 2000e analyzer (Quantuchrome,
Boynton Beach, FL). The total surface area (SBET) was calculated
acetonine was formed by the cyclization reaction of enamine
intermediate 1 and acetone. Besides, mesityl oxide was
activated by the formation of imine intermediate 2 followed
by the aldol condensation of acetone to generate 2,6-
dimethylhepta-2,5-dien-4-imine. 2,6-Dimethylhepta-2,5-dien-
4-imine reacted with one molecule of ammonia to form
imine intermediate 3, which was easily converted to
triacetonamine for the lack of conjugated system [16,17].
from the linear part of the BET. The micropore volume (Vmicro
)
and the external surface area (SEXT) were estimated by the t-plot.
The pore size distributions were obtained using the method of
Barret–Joyner–Halenda.
The IR spectra of adsorbed pyridine were recorded using a
Thermo Nicolet Nexus 470 spectrometer (Thermo Electron
Corporation, Waltham, MA) equipped with a heatable and
evacuatable IR cell containing CaF2 windows. The Brønsted
and Lewis acid sites could be distinguished by the bands of
CONCLUSIONS
The continuous synthesis of triacetonamine was achieved
with HY zeolite as catalyst, and the optimum reaction condi-
tions (temperature, 60°C; molar ratio of ammonia and
acetone, 1:6; GHSV, 20.7 hÀ1) were obtained. The alkali-
treated HY with different structure and acidities were pre-
pared and examined. The results indicated that the acid sites,
especially BASs, played an important role on the conversion
of acetone and the selectivity of triacetonamine. At last, the
generation mechanisms of triacetonamine and impurities
were speculated.
chemisorbed pyridine.
NH3-temperature-programmed desorption was performed on a
TP-5000 instrument (Tianjin Xianquan Industry and Trade
Development Co., LTD., Tianjin City, China) with a thermal
conductivity detector. Typically, 0.1-g sample was pretreated at
800°C in N2 flow (30 cm3/min) for 90 min. Adsorption of dry
ammonia took place at 120°C for 120 min. Desorption of
ammonia was done at a rate of 15°C/min from 120°C up to
650°C under Ar flow(10 cm3/min).
EXPERIMENTAL
REFERENCES AND NOTES
Catalyst preparation.
Commercial zeolite catalysts were
[1] Taylor, D. B.; Milligan, B. American Patent 4831146, 1989;
Chem Abstr 1989, 111, 173991y.
[2] Julius, M.; Hermeling, D.; Siegel, H.; Harder, W. American
Patent 5856494, 1998; Chem Abstr 1998, 128, 192560t.
[3] Kruse, W. M.; Stephen, J. F. American Patent 4734502A,
1988; Chem Abstr 1988, 110, 173089s.
[4] Haruna, T.; Nishimura, A.; Sugibuchi, K. American Patent
4663459A, 1985; Chem Abstr 1986, 104, 88441a.
[5] Weiner, H. Biochem 1969, 8(2), 526.
[6] Hall, H. K., Jr. J Am Chem Soc 1957, 79, 5445.
[7] Orban, I.; Lind, H.; Brunetti, H.; Rody, J. American Patent
3960875A, 1976; Chem Abstr 1976, 85, 32863y.
[8] Orban, I.; Lind, H.; Brunetti, H.; Rody, J. American Patent
3953459A, 1975; Chem Abstr 1975, 82, 156093a.
[9] Orban, I.; Lind, H.; Brunetti, H., Rody, J.; Rasberger,
M. American Patent 3959295A, 1976; Chem Abstr 1976, 85, 32862t.
[10] Nakahara, Y.; Kubota, N.; Hirai, B.; Haruna, T. American
Patent 4418196A, 1983; Chem Abstr 1983, 99, 53610u.
[11] Malz, R. E.; Son, Y.-C.; Suib, S. L. American Patent
20020128482A1, 2002; Chem Abstr 2002, 137, 216882s.
[12] Masaru Ogura; Shin-ya Shinomiya; Junko Tateno; et al. Appl
Catal A Gen 2001, 219, 33.
supplied by the Catalyst Plant of Nankai University (Tianjin
City, China). The alkaline treatment of HY was performed
with aqueous solutions of 0.03, 0.50, and 1.00 mol/L NaOH.
Forty grams of HY was put into 150 mL of NaOH solution,
and the solution was kept at 100°C for 5 h under stirring.
The zeolite was filtered and then washed with distilled water
until the filtrate pH was neutral (pH = 7 ~ 8). After drying,
the alkali-treated HY was treated with 150 mL of 1 mol/L
NH4NO3 at 100°C for 3 h twice followed by calcination at
500°C for 4 h. Those obtained catalysts were denoted by
HY-0.03M, HY-0.50M, and HY-1.00M, respectively.
Catalytic reaction.
The condensation of acetone and
ammonia was carried out in a tubular, fixed-bed reactor with an
inner diameter of 15mm and a length of 650 mm, which was
charged of 40mL catalysts. Acetone was dosed into the reactor by
syringe pump. The ammonia flow rate was set by S49 33/MT
mass gas flow controller. The temperature in the reaction zone
was measured by a thermocouple located in the center of the tube
and connected to a proportion integration differentiation cascade
controller. The reaction mixture was analyzed by GC with a 30-m
SE-54 capillary column (Chromatographic Technology R&D
Center, Lanzhou Institute of Chemical Physics, Chinese Academy
of Sciences) and FID detector. Moreover, the components of the
reaction mixture were identified by GC-MS equipped with HP-5
capillary column (30 m × 0.25 mm, 0.2μm film thickness) and an
ion trap MS detector.
[13] Mochizuki, H.; Yokoi, T.; Imai, H.; et al. Appl Catal A Gen
2012, 449, 188.
[14] Rac, V.; Rakić, V.; Miladinović, Z.; et al. Thermochim Acta
2013, 567, 73.
[15] Shen, B.; Qin, Z.; Gao, X.; et al. Chinese J Catal 2012, 33(1), 152.
[16] Xu, T.; Zhang, J.; Haw, J. F. J Am Chem Soc 1995, 117, 3171.
[17] Nováková, J.; BoSáček, V.; Dolejšek, Z.; Kubelkova, L. J Mol
Catal 1993, 78, 43.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet
Tian, Jun
