A R T I C L E S
Lee et al.
110 g of hydroxylamine-o-sulfonic acid (Aldrich) in 317 g of formic
acid was added dropwise. The addition was carried out over about 15
min and a slight exotherm developed. The reaction is heated to reflux.
Overnight the reaction went from a pale yellow solution to black.
TLC (98/2 CHCl3/CH3OH on silica) showed the reaction was complete.
The reaction was carefully poured onto 2 kg of ice and then carefully,
the pH was raised to about 12 with 50% NaOH solution. This aqueous
phase was next extracted 3 times with methylene chloride and these
extracts were dried with sodium sulfate. The dried extract was then
stripped under reduced vacuum, leaving 78 g of dark oil that
crystallized. The dark oil, a potential mixture of two imide isomers,
was further purified by column chromatography. The crude material
was dissolved in a minimum of methylene chloride and then loaded
onto a silica gel (230-400 mesh), 1 kg, loaded in a slurry with
chloroform. About 6 L of 98/2 chloroform/methanol was run over the
column and multiple fractions were collected and analyzed by TLC.
61 g of light brown solid were recovered.
The mixture of imides was reduced with lithium aluminum hydride
(LAH). A 5 L three-neck round-bottom flask equipped with an overhead
mechanical stirring system was used. The 61 g of product from the
column purification was dissolved in methylene chloride and this
solution was added dropwise to the main flask, which already contained
1.1 L of anhydrous ether and 44 g of LAH (Aldrich). As the addition
began, there was an exothermic evolution of gas. The reaction
temperature was controlled by the use of an acetone/dry ice bath around
the flask. The addition was carried out over 0.5 h. The dry ice bath
was removed so that the reaction could come to room temperature
slowly. The reaction was then stirred overnight at room temperature.
The next day, 44 g of water was slowly added dropwise with much
gas evolution. Some additional methylene chloride was added to make
up for the volume of ether lost (in the hood!) from the gas evolution.
44 g of 15% NaOH solution was added next. This was followed by
the addition of 131 g of water while good stirring was maintained
throughout. The white solid byproduct was washed with methylene
chloride and this wash was added to the existing two-phase system
after solids were removed by filtration. The methylene chloride extract
was dried with sodium sulfate. Recovery of the product from removal
of solvent gave an oily solid. This was treated with ether and the
remaining solids were filtered. Separate workup of the ether extract
gave 42 g of an orange oil.
A 21 g sample of the oil was converted into the mixture of 1 and 2
by reaction with 58 g of methyl iodide (added dropwise) to 20.4 g of
potassium bicarbonate and the oil in 140 mL of methanol. This
alkylation was carried out at room temperature for over a week. The
reaction was stripped down to dryness and the product was recovered
into chloroform. The product was then obtained by removal of the
chloroform.
The two isomers were separated by fractional recrystallization from
hot acetone and methanol combined. The first crop consisted of 1. A
subsequent crop yielded isomer 2. 13C NMR of the products verified
the separate identity.
In some instances, when isomers arose from the Beckmann rear-
rangement, a separation was carried out at the imide stage, using column
chromatography. A typical procedure was to dissolve the mixture in a
minimum of chloroform, load it onto a column of silica gel (230-400
mesh), and elute with 2%, 98% methanol/chloroform.
In other cases, the product can be prepared from available cyclic
amines such as decahydroquinoline. A representative procedure is as
follows: The two different isomeric decahydroquinoline derivatives
(cations 15 and 16) were prepared by ethylation of the decahydro-
quinoline. Decahydroquinoline (24.8 g; Aldrich, mixture of isomers)
was dissolved in 170 mL of methanol. Potassium bicarbonate (26 g)
was slurried into this solution in a 500 mL round-bottom flask, stirred
by use of a magnetic stir bar and hot plate. Using a dropping funnel
with an equalizer arm, 67.4 g of iodoethane was added dropwise over
a 15-min period. No exothermal reaction was detected for this room
temperature addition. With a heating mantle, the reaction was slowly
brought to reflux in the presence of a condenser. Heating was continued
for 2 days. After cooling the mixture to room temperature and stripping
off the methanol, the solids were triturated with 250 mL of chloroform
(to extract the product away from inorganic solids). Organocations were
recovered from removing the chloroform and were then recrystallized
in a minimum of hot isopropyl alcohol. The collected product was a
mixture of isomers (cis and trans configurations). A further crystal-
lization from hot methanol/acetone (see above) yielded a separation
with the first and second crop consisting of the two separate isomers,
15 and 16.
The iodide salt was converted into the hydroxide form via treatment
with BioRad AG 1-X8 hydroxide exchange resin. The zeolite syntheses
were carried out with use of the hydroxide form. Cations 8-10 were
similarly prepared with different alkylation reagents.
2. Zeolite Synthesis. The conditions for synthesizing zeolites in the
presence of these organocations recently have been described by us in
a prior publication.2 A representative example was given for each of
the 5 SiO2/Al2O3 ratios. One example of synthesis with sodium borate
was also described.
In a representative zeolite synthesis, for the SiO2/Al2O3 ) 100
example, the reagents are combined in the Teflon cup of a Parr
Chemical Company 23 mL Stainless steel reactor. Reheis F-2000
alumina hydroxide (0.03 g, 53% Al2O3) was dissolved in a basic
solution composed of 2.15 mmol of the organocation as the hydroxide
form and 1.5 mmol of sodium hydroxide, both bases in a total of 11.75
g of water. Cabosil M-5 (0.90 g, 97% SiO2) was blended into the
solution. The reactor was sealed and heated at 170 °C and rotated at
43 rpm for 6-12 days. When solids settled on the bottom of the cup,
the contents were washed in a filter, dried, and examined by powder
X-ray for phase determination.
3. Characterizationof Zeolite Crystallization Products. The zeolite
products were characterized initially by X-ray powder diffraction.
Experiments were run on a Siemens D-500 instrument. Further
characterization was carried out, in particular the relationship to SSZ-
48. The data taken at the Brookhaven National Lab Beamline were
from a sample that had been calcined to 600 °C, then loaded into a 1
mm capillary tube which was sealed while under vacuum and at 350
°C. The X7A synchrotron beamline was used for data collection.
4. Microscopy. The scanning electron micrographs were taken on
a Hitachi S-3200 instrument. The TEM micrograph was taken on a
JEM 4000-EX, using techniques that have been described.17
5. NMR. One- and two-dimensional 1H and 13C NMR spectra were
obtained for the organocations in solution (CDCl3) on a Varian INOVA-
500 (500 MHz for 1H, 125 MHz for 13C) spectrometer. 13C cross
polarization magic angle spinning (CPMAS) spectra of the iodide salts
(prior to hydroxide ion-exchange) were recorded on a Bruker DSX-
500 MHz spectrometer, using a 4 mm CPMAS probe (detailed
experimental parameters are given in figure captions). The 13C MAS
and CPMAS experiments were performed for as-synthesized zeolites
using a Bruker DSX-200 (200 MHz, 50 MHz) or a Bruker AM 300
spectrometer that was modified for solid NMR measurements.
Results and Discussion
1. Generation and use of [l.m.0] Organocations. Figure 5
gives a scheme for the organic synthesis of candidate molecules
starting from 2-decalone (a [4.4.0] ring system). One can see
that the eventual Beckmann rearrangement lactam provides for
a ring expansion into a [4.5.0] system. The scheme depicts
starting with a ketone at the 2 position and generating isomeric
amides at the 2 and 3 positions. A discussion of the reaction
product probabilities for different systems has been given by
Krow.18 In our work, we found this combination to give superior
(17) Wagner, P.; Terasaki, O.; Ritsch, S.; Nery, J. G.; Zones, S. I.; Davis, M.
E.; Hiraga K. J. Phys. Chem. B 1999, 103, 8245-50.
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7028 J. AM. CHEM. SOC. VOL. 124, NO. 24, 2002