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Bethel College
Creating a Greener Organic
Chemistry Lab
Jose A Rojas
05/19/2010
Chemistry 482 Senior Seminar
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Table of Contents
I.
Abstract
3
II.
Background
4
III.
Methods and Experiments
7
a. Reagents
7
b. Synthesis of Catalyst
7
c. General Oxidation Reaction Procedures
8
d. Oxidizing Reactions Using K-OMS-2
8
e. Oxidizing Reactions Using H-K-OMS-2
9
f.
10
Oxidizing Reaction using recycled H-K-OMS-2
g. Oxidation using 0.4 g of H-K-OMS-2 by Organic Chemistry Class
11
h. Apparatus and Procedure
11
IV.
Results
13
V.
Discussion
14
VI.
Conclusion
17
References
19
Acknowledgments
20
Appendix1
21
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I.
Abstract
The purpose of this project was to develop a green lab that could be used for a lab period for
students in Organic Chemistry. The goals were to find a catalyst that was less toxic than ones
currently in use for the oxidations of alcohols to ketones and to complete the reaction and
procedures needed for separation and purification within a three hour lab period. The lab
developed is based on the oxidation of the alcohol 9-flurenol into the ketone form 9-flurenone.
The catalyst originally used was a polymer-supported 𝐶𝑟𝑂3 , and the time for the completion of
the reaction was an hour plus the time needed for all the other procedures needed to isolate
the ketone. Octahedral molecular sieves (OMS) have shown a great potential for the
oxidative catalysis of alcohols. These kinds of catalysts were investigated earlier by the
Bethel graduate Omar Hasan in his seminar project last year. He studied a number of
different OMS-2 type catalysts. However, in order to reach the goals of a green lab
catalyst K-OMS-2 and H-K-OMS-2 were used because of their low toxicity levels. The
results of this study indicated that the H-K-OMS-2 catalyst was able to complete the
oxidation reaction within 20 minutes, while the K-OMS-2 catalyst did not work favorably
toward goals. The lab developed in this project proved to be successful as demonstrated
by the very good results obtained by the Organic Chemistry II class which recently tested
the laboratory procedure.
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II.
Background
Omar Hasan, a bethel grad, in his undergraduate research worked with different catalysts that
enhanced the oxidation of alcohol into ketones and aldehydes. Hasan was working with OMS-2, a
porous manganese oxide octahedral molecular sieve. It is called OMS-2 because it has a 2x2 octahedron
crystalline structure. Hasan indicated that the
porosity of the OMS-2 give it the ability to
channel some of the positive charges for
superior catalytic activity. Figure 1, shows the
Figure 1. Structure of OMS-2.
structure of OMS-2. The OMS-2 channels have porous openings of 4.6Å. The OMS-2 structures are
comprised of units of 𝑀𝑛𝑂6
octahedron. OMS-2 consists of
manganese oxide, 𝑀𝑛𝑂2 , that share
corners and edges that line up
forming the 𝑀𝑛𝑂6 octahedron. Even
though, OMS-2 serves as a highly
active thermally stable catalyst when
ion exchanged with other metal ions,
for example, vanadium and nickel, we
will focus on the original form of
Figure 2, Proposed Mechanism for Catalyzed Alcohol Oxidation by OMS-21.
OMS-2 (K-OMS-2) and on the hydrogen doped form of the OMS-2 (H-K-OMS-2). The hydrogen doped
form is achieved by washing the K-OMS-2 with 1.0 M 𝐻𝑁𝑂3 . By doping OMS-2, Hasan indicated that
this significantly enhanced the conversion of alcohols to either the ketone or aldehydes form, which
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suggested that the oxidation was
enhanced by Bronsted acid sites1. In
figure 3, there is a list of the conversion
of several alcohols and their conversion
percentages when using the acid doped
form of OMS-2, as well as, the original
form K-OMS-2. The proposed oxidation
mechanism for these oxidation
reactions is illustrated in figure 2. Hasan
also mentioned that H-OMS-2 and KOMS-2 apart from being very stable
catalyst that they can be store and be
active for up to two years. Hasan found
that these oxidizing reactions ended up
Figure 3. Oxidation of Alcohols Using K-OMS-2 and H-K-OMS-2.1
as liquid products which eventually
were analyzed by gas chromatography taking a very long time; this technique was use for qualitative
purposes.
The search for greener catalysts that can oxidize reactions is becoming more and more popular
today. In experiment 14 of the book Green Organic Chemistry2, the focus is on oxidation chemistry,
where a secondary alcohol, 9-flurenol, is oxidized into its ketone form, 9-fluorenone, by using a polymer
containing a reactive form of 𝐶𝑟𝑂3 as their oxidizing agent. Figure 4 shows the reaction. The polymersupported 𝐶𝑟𝑂3 oxidizes organic substrates very readily. In the introduction to the lab, it mentions that
typical oxidizing agents are often corrosive, toxic, and environmentally damaging, and that the
development of environmentally benign procedures for the adjustment of oxidation state remain an
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important research goal2. In their lab, the experiment calls for refluxing the reactions, thin-layer
chromatography (TLC) for checking the
progress of the reaction as well as
for qualitative and quantitative
analysis, rotary evaporation of the
Figure 4. Oxidation reaction from 9-fluorenol to 9-flurenone
solvent and the recrystallization and melting point determination for qualitative analysis. The procedure
used 1 gram of the alcohol and 5 g of the dry polymer-supported 𝐶𝑟𝑂3 catalyst to 35 ml of toluene in a
100 ml round bottom flask containing a magnetic bar. It was refluxed for about an hour while stirring
and the reaction was check by TLC on silica plates for completion. Reaction was cooled to room
temperature, filtered to remove the catalyst, removed the solvent with a rotary evaporator and
weighted the crude product. Finally, recrystallyzed the crude product with a mixture of ethanol and
water, weighted the recrystallized product and took the product’s melting point. The catalyst can be
treated and stored ready to be reused.
Green chemistry is becoming the most popular way of doing chemistry. In order to do Green
Chemistry, one or more of the twelve principles of green chemistry need to be follow when doing an
experiment. For example, in order to achieve the goal of creating a greener lab some of these principles
had to be followed. The followings are green chemistry principles provided by the Environmental
Protection Agengy (EPA) website that were followed through this project: preventing waste, less
hazardous chemical syntheses, designing safer chemicals, design for energy efficiency, catalysis and realtime analysis for pollution prevention. By combining the OMS-2 catalysts that Hasan studied with
following the procedures and using the reagents that were used in experiment 14, in the book of Green
Organic Chemistry, the goal for this project to develop a “Green Lab”. The reaction needed to be
completed in less than a three hour period, so that this lab could be used during a lab period for the
Organic Chemistry class in Bethel College. This project focused on using Hasan’s greenest catalyst which
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includes the doped catalyst H-K-OMS-2 and the original form K-OMS-2. The oxidation reaction of 9fluorenol to 9-fluorenone is expected to work since Hasan was able to get very good conversion
percentages when oxidizing phenyl ethanol, as well, as benzhydrol with the doped OMS-2 form H-KOMS-2 and K-OMS-2. It should be a noted that Hasan used a vanadium\𝑀𝑛𝑂2 catalyst which in most
cases had very high conversion percentages. However, for our purposes of a green lab, this form of
catalyst will not work since vanadium is very toxic. In the experiment 14, they used a polymersupported 𝐶𝑟𝑂3 as their catalyst. 𝐶𝑟𝑂3 itself is much more toxic than our manganese oxide octahedral
sieves which help us achieved our goal of a green lab. Lastly, the catalyst use for this project should be
tested to see if it can be recycled or not in order to favor our purposes to create a green lab.
III.
Methods and Experiments
A.
Reagents
All reagents used were analytical grade and purchased from SIGMA-ALDERICH chemical supplier.
Ultrapure deionized water (UDW) was used to prepare materials. Water was purified by a compact
ultrapure water system by Barnstead.
B.
Synthesis of Catalysts
1.
K-OMS-2
4.3484 g. of 𝐾𝑀𝑛𝑂4 was placed in a 100 ml beaker and dissolve in 75 ml UDW. 6.5272 g.
of 𝑀𝑛𝑆𝑂4 . 𝐻2 𝑂 was placed in a 250 ml round bottom flask and dissolved in 22.5 ml UDW along
with 2.3 ml concentrated 𝐻𝑁𝑂3 . Then the initial solution of 𝐾𝑀𝑛𝑂4 was carefully added to the
𝑀𝑛𝑆𝑂4 . 𝐻2 𝑂 solution. From this mixture a very dark mud like precipitate was precipitated. This
mixture was reflux at about 100℃ for 24 hours. The product was vacuum filtered using a paper
filter, washed with 7 small portions of UDW totaling 100 ml and dried at 120℃ overnight in an
oven. After drying, the product was separated from the filter paper and ground to a powder by
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mortar and pestle. The product was then stored in a sealed glass vile. The final yield was 6.1140
g. of K-OMS-2.
2.
H-K-OMS-2
0.9973 of the K-OMS-2 was exchanged with 200 ml of 1.0 M 𝐻𝑁𝑂3 . This was done with vigorous
stirring at room temperature for 2 hours. The product was then filtered by vacuum filtration and
a paper filter. The product was vacuum filtered using a paper filter, washed with 7 small
portions of UDW totaling 100 ml and dried at 120℃ overnight in an oven. After drying, the
product was separated from the filter paper and ground to a powder by mortar and pestle. The
product was then stored in a sealed glass vile. The final yield was 0.9284 g. of H-K-OMS-2.
C.
General Oxidation Reaction Procedures
9-hydroxyfluorene (0.182 g.) and K-OMS-2 catalyst (0.4 g.) were refluxed with toluene
(10 ml) in a round-bottom-flask (100 ml) containing a magnetic stir bar for 20 minutes. The
reaction was followed every ten minutes by thin layer chromatography (TLC) on silica plates,
developed with 30% acetone in hexanes. The reaction was cooled to room temperature; catalyst
was removed by gravity filtration and washed with small amounts of toluene. Catalyst was dried
and stored for future possible use of it. The solvent was removed by rotary evaporatorion. Small
stream of air used to remove the last traces of the solvent. The crude product was recrystallized
from a mixture of 50:50 ethanol/water and melting point determined.
D.
Oxidation reactions using K-OMS-2
1.
Experiment #1
9-hydroxyfluorene (0.1824 g) and K-OMS-2 (0.505 g) catalyst were added. The reaction was
refluxed for about an hour and a half. The reaction was not completed after this time when it
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was checked by TLC. The recrystallize product was a white and yellow precipitate, nothing like
our desire product, probably a mixture of starting materials and product.
2.
Experiment # 2
9-hydroxyfluorene (0.1824 g) and K-OMS-2 (0.501 g) catalyst were added. The reaction was
refluxed for about an hour and a half. The reaction was not completed after this time when it
was checked by TLC. The recrystallize product was a white and yellow precipitate, nothing like
our desire product, probably a mixture of starting materials and product.
3.
Experiment #3 (using more catalyst)
9-hydroxyfluorene (0.182 g) and K-OMS-2 (0.2 g) catalyst were added. The progress of the
reaction was followed every ten minutes by thin layer chromatography (TLC) on silica plates,
eluting with 30% acetone in hexanes. The reaction never went to completion after the hour and
a half, it seemed like the reaction was still going, and the spots in the silica plates looked like if
there was a 50:50 mixture of starting material and product.
E.
Oxidizing Reactions using H-K-OMS-2
1.
Experiment #1
9-hydroxyfluorene (0.1823 g) and H-K-OMS-2 catalyst (0.05 g.) were added. The reaction was
refluxed and stirred for about 40 minutes. After 40 minutes, the solvent was evaporated and we
were unable to continue with the experiment.
2.
Experiment #2
9-hydroxyfluorene (0.1827 g) and H-K-OMS-2 catalyst (0.0505 g.) were added. The reaction was
not complete when checked with TLC after an hour and a half of refluxing. The recrystallized
product was a light yellow precipitate with a melting point range of 104-118 ℃. The wide
melting point range indicates impurity and that it is probably a mixture of starting material and
product. The recrystallized product weighted 0.0737 g. with a percent yield of 40.79%.
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3.
Experiment #3 (using more catalyst)
9-hydroxyfluorene (0.1824 g) and H-K-OMS-2 catalyst (0.2 g.) were added. The reaction was
complete after an hour and a half and the solvent had a yellow color. The recristallized product
was very fine yellow crystals, as expected and its melting point range was 78.5-82 ℃ . The
melting point range was within ±3℃ of the melting point of the desired product, which means
that the product is pure.
4.
Experiment #4 (even more catalyst)
9-hydroxyfluorene (0.1830 g) and H-K-OMS-2 catalyst (0.4074 g.) were added. The reaction was
complete after 20 minutes. The progress of the reaction was checked every 5 minutes for
completion. The solvent was of a yellow, a good indication. The recrystallized product was
yellow crystals, and its melting point range was 81.5-84 ℃ . The recrystallized product weighted
0.0245 g. with a percent yield of 13.56%.
5.
Experiment #5
9-hydroxyfluorene (0.1827 g) and H-K-OMS-2 catalyst (0.405 g.) were added. Reaction complete
after 20 minutes. The product was yellow crystals, melting point 79.5-83.5 ℃ .
6.
Experiment #6
9-hydroxyfluorene (0.1833 g) and H-K-OMS-2 catalyst (0.4022 g.) were added. The reaction was
complete after 15 minutes. The product was yellow crystals, melting point 79-83 ℃ .
7.
Experiment #7
9-hydroxyfluorene (0.1836 g) and H-K-OMS-2 catalyst (0.4048 g.) were added. Reaction
complete after 20 minutes. The product was yellow crystals, melting point 81.5-84.3 ℃ .
8.
Experiment #8
9-hydroxyfluorene (0.1834 g) and H-K-OMS-2 catalyst (0.4015 g.) were added. Reaction
complete after 20 minutes. The product was yellow crystals, melting point 80.5-83.5 ℃ .
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F.
Oxidation using recycled H-K-OMS-2
1.
Experiment #1
9-hydroxyfluorene (0.1822 g) and recycled H-K-OMS-2 catalyst (0.4033 g.) were added. The
reaction was refluxed for about an hour and a half. The progress of the reaction was followed
every ten minutes by TLC. It seems like the reaction never went to completion, this could be
cause by the catalyst being completely doped from previous reactions.
G.
Oxidation using 0.4 g of H-K-OMS-2 by Organic Chemistry Class
The organic chemistry class was able to run this experiment in order to see if, in
fact, this lab could work as a lab period for future Organic Chemistry courses. The
organic chemistry class ran seven reactions using the same procedures in all of them. The
procedure that the class followed is shown in appendix 1.
H.
Apparatus and Procedure
The synthesis of the catalyst as well as the oxidation of the alcohol had the same set up. The
apparatus shown below (image 1) was set up so that two reactions could be running at the same
time; by doing this we saved water as well as time. The round bottom flask was loaded with
Image 1, Set up
used in synthesizing
catalysts and
oxidation reactions
Condenser
Round Bottom Flask
Heating Mantle
Stirrer
Drain
Water Source
Temperature Control
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reactants in order for the reaction to proceed. In all the oxidation experiments, a 100 round
bottom flask was use, and a 250 ml was use for the synthesis of the catalyst. Once the reactions
were completed, the catalyst was dried and grounded to a powder by mortar in order to be
a)
b)
zero time
10 min
20 min
Image 2a, shows the TLC silica plates already spotted at zero time, ten minutes and 20 minutes after
reaction began. Image 2b, shows the same silica plates under UV light, where we can see the spots.
use. The oxidation reactions were analyzed by TLC, image 2 shows the TLC set up that was use to check
the progress of the reaction as well as its completion. The silica plates were spotted with the starting
material dissolve in toluene, the reaction, and the
desire product dissolve in toluene. The reaction
spot was compared to that of the starting material
as well as the desire product. By doing this, we
were able to analyze the reactions qualitatively
and somewhat quantitatively. As mentioned
before, the oxidizing reactions were cooled to
room temperature, and then filtered before
evaporating the solvent via rotary evaporator.
Image 3, Electrothermanl melting point apparatus
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Once we had our crude product, we recrystallized it and took its melting point using an electrothermal
melting point apparatus (image 3). Taking the melting point is one of the most effective methods to
check for the quality of the product. NMR was another option but we decided that taking the melting
point took less time and a better method.
IV.
Results
Since we could not find anything while using K-OMS-2 for our reactions, the results are
based on the results that we have for the reactions with H-K-OMS-2 that were done by the
Organic Chemistry class and me.
Table 1. Oxidation Results using H-K-OMS-2
Experiments
Experiment #1
Experiment #2
Experiment #3
Experiment #4
Experiment #5
Experiment #6
Experiment #7
Experiment #8
Amount of
H-KOMS-2
0.05
0.05
0.2
0.4074
0.4
0.4022
0.4048
0.4015
Melting point
range(°C)
-104-118
78.5-82
81.5-84
79.5-83.5
79-83
81.5-84.3
80.5-83.5
Recrystillized
product (g)
-0.0737
-0.0245
Reaction
Time
-1.5 hr
1.5 hr
20 min
20 min
15 min
20 min
20 min
% yield
-40.79
--13.56
Table2. Oxidation Results using H-K-OMS-2 from the Organic Chemistry Class
Experiments
Experiment #1
Experiment #2
Experiment #3
Experiment #4
Experiment #5
Experiment #6
Experiment #7
Amount of
H-KOMS-2
0.4
0.4
0.4
0.4
0.4
0.4
0.4
Melting point
range(°C)
80-82.7
83.1-83.6
82-85
82-83
80-83
80-83
79.5-82.5
Recrystillized product
(g)
0.059
0.02
0.078
0.09
0.09
0.34
0.01
Reaction
Time
25 min
20 min
20 min
20 min
20 min
25 min
20 min
% yield
32.65
11.07
43.17
49.81
49.81
188.2
5.53
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The results in table 1 were the ones that I recorded from my reactions. Notice that only seven of
the eight reactions are on the table. The first experiment was not completed because the
solvent dissolved after taking several samples from the solution, as I mentioned in the
procedure segment for this particular experiment. From the results in table 1 and 2 we can see
that after adding 0.4 grams of the H-K-OMS-2 catalyst, the reaction went to completion in an
average of 20 minutes and with very good melting point ranges, by 80-83 ℃ being the melting
point of 9-fluorenone. Most of the melting point ranges were within ±3℃ of our desire melting
point range, which means that the final products were mostly pure.
By looking at the results there is a greater confidence in that the H-K-OMS-2 catalyst works well
for the oxidation reaction that we wanted, 9-flurenol to 9-flurenone. From the data we are
confident to state that the reaction can be carry to completion within 20 minutes, this is a
decrease in time from one hour to 20 minutes, saving 40 minutes of time that we can use for
the following procedures in the lab. Also, from the data we are confident that the product is
pure and that future reactions can obtain this purity by following the procedures stated well.
Lastly, this lab proves that it can be repeatable by having several Organic Chemistry students
doing it, while following the procedures provided, and getting the results that were expected in
every case.
V.
Discussion
There are many things to note in the results, as well as, in the procedures. First, there was not
data collected from the experiments done with the K-OMS-2 catalyst since the reactions never went
to completion after an hour and a half. One thing that could have been done is that the reaction
could have been run for more time and be completed after three or four hours. Hasan’s oxidation
reactions were run for four hours using different catalysts, and as mentioned before, he was able to
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obtained favorable results using K-OMS-2 as well as H-K-OMS-2. But since my goal was to reduce the
time that take for the reaction to be completed, different options had to be considered. One of the
options was to increase the amount of catalyst but this did not work either. The reaction was still
not complete after an hour and a half, which was the time limit for our purposes. When the melting
point was taken from these different reactions using K-OMS-2 as the catalyst, there were broad
melting point ranges, for example, in one there was a range of 104-118℃. This was a broad range
which indicated impurity in our product. Also, the melting point of the starting material, 9-flurenol,
is 153-154℃ and the melting point for the desire product, 9-flurenone, is 80-83℃; this melting point
range were not even close to the starting material or the desire product. This indicated that the
product was a mixture of starting material and product, and possibly some other kind of
contamination. This is the reason why the results from K-OMS-2 were not presented, because they
did not help towards achieving the goals for this project
Another point to notice is that the results obtained while using H-K-OMS-2, as you can see in
table 1, most of them did not include the mass after recrystallization, only the melting point ranges.
This happened because the main thing was to prove that the product was our desired product. This
is the reason why only the melting point ranges were taken, since this is a very good method in
order to analyze sample qualitatively. Another reason is that when the reaction is filtered, the
solvent is evaporated and the crude product recrystallized, there is a great amount of our product
that is been lost in each of those procedures; so, the percent yield most of the times is very small.
There were some instances that the percent yields were more than 100% which indicated that there
was some kind of contamination of the product with the solvent that was not able to be evaporated.
This happened to one of the persons in the organic chemistry lab, but this is normal when someone
has not done these kinds of procedures before.
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There is another point that should be noted. There was a great amount of confusion from the
organic chemistry class and from myself about the amount of the mixture of ethanol and water used
to recrystallized the crude product. From my part, at the beginning of my project I was uncertain
about how much ethanol and water to use, the instructor indicated that I was supposed to use the
least amount of ethanol and water as possible so that recrystallization could happen faster. After
doing several recrystallizations, I was able to find a way to do it, even though I was not keeping track
of the amount of ethanol and water that I was using. So, what I was doing was to dissolve the crude
product in a small amount of hot ethanol, then pour a small amount of water until I could see the
cloudy point, where a white precipitate is form, and then heat the solution and let the precipitate
dissolve. After it was dissolve, I let the solution cool down and recrystallize. This technique was not a
very good one in order to save time, but it worked. The organic chemistry students ran into similar
problems, in the procedures that I provided I did not indicated how much ethanol or water to add
which was somewhat confusing for some of them, but with the help of their instructor they were
able to complete this lab almost perfectly. The amount of ethanol and water to use for
recrystallization is the only thing that I could not find a good way to do it, but with the help of an
instructor, someone can definitely follow this lab’s procedure and finish it within three hours, since
this was one of my goals.
Lastly, it has noted that the best catalyst for this experiment is the H-K-OMS-2, which is better in
toxicity than the polymer-supported 𝐶𝑟𝑂3 used in the original procedure that was use as a base to
this project. For this experiment, there was less amount of H-K-OMS-2 used compared to what they
were using in the experiment that was been followed. They used 5 g. of polymer-supported 𝐶𝑟𝑂3
for every 1 g of 9-flurenol that they used. In our case, the amount of catalyst that we used was 0.4 g
of H-K-OMS-2 for every 1 mmol (0.182g) of 9-flurenol. Also, the last thing that we should notice is
that when we tried to use the recycled catalyst, the reaction never went to completion after an hour
Rojas 17
and a half. This could be done to the fact that the “recycled” catalyst that was use was never
reactivated, in other words, the catalyst was suppose to be wash with 1.0 M 𝐻𝑁𝑂3 which could
have enable the catalyst to react again with 9-flurenol by being doped once again with the acid. This
was never done and it would be a very interesting small project to do, where someone can run a
couple of reactions following my procedure and recycling the catalyst. Eventually wash the catalyst
with 1.0 M 𝐻𝑁𝑂3 to reactivate it and do a third reaction in order to see if the catalyst can, in fact,
be recycled and reuse to favor our purposes for a greener lab. Hasan in his project indicated that it
might be more expensive to try to recycle the catalyst and reuse it than making new catalyst. This
could be true but in order to do new catalyst, there is a two day wait, a day where the catalyst is
synthesis, and another to dry it and then two more hours for washing the catalyst with 1.0 M 𝐻𝑁𝑂3 .
So, it might be worth trying to save and recycle the catalyst for future reactions.
VI.
Conclusion
There are a few conclusions that can be drawn from this project. First, the goal of doing a
greener lab was achieved by having the less toxic catalyst work very well for the desired reaction,
which reacted in 40 minutes less than the catalyst originally used for this experiment. Secondly, the
goal of putting together a lab that could work for future Organic Chemistry courses was achieved by
having the present Organic Chemistry Class run the experiment and obtaining very good results,
which indicated that this experiment can be reproducible and with very good results. The organic
class was able to obtained pure products that were analyzed by melting point, a very good
qualitative methods to use. Thirdly, the goal to be able to recycle the catalyst was not achieved, but
further investigation needs to be done in order prove this. This is a project that someone in the
future may perform and include to this project if the results come up to be favorable.
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From the results that were obtained, there are possibilities that different organic compounds
may be able to be oxidize while using this same procedure with the same catalyst. Hasan was able to
oxidize different alcohols using this kind of catalyst, even though the procedures that he was
following were different to the procedures followed during this project. This could be another
project where someone could use this procedure while working with different alcohols. The best
way to do these reactions is to do them as green as possible, and hopefully future students can be
able to try and do a follow up in this project so that their findings can indicate us whether or not this
procedure is good for a wide range of alcohols.
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References
1. Hasan, O., Oxydation of Organic Alcohols Using a Vanadium Substituted Manganese Oxide
Catalyst, Bethel College Senior Seminar, 2009, 1-51.
2. Kenneth, D. M.; Hutchison, J. E. Green Organic Chemistry: Strategies, Tools, and Laboratory
Experiements, Brooks and Cole: USA, 2004, exp. 14, 197-200.
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Acknowledgments

Dr. Gary Histand

Dr. Richard Zerger

Dr. Dwight Krehbiel

Organic Chemistry Students

Family and Friends
Rojas 21
Appendix 1- Organic Chemistry Class Procedure
H-K-OMS-2 OXIDATION OF 9-FLUORENOL TO 9-FLUORENONE
Background:
In this experiment, 9-fluronone is prepared by the oxidation of 9-fluorenol. The
oxidation is carried out by using an oxidative catalyst called H-K-OMS-2* (octahedral
molecular sieves). Even though the toxicity of this catalyst is unknown, it is believe to be
less toxic and corrosive than the typical oxidizing reagents used for this reaction, such
as 𝐶𝑟𝑂3.
Overall Reaction:
Procedure:
Set up a reflux apparatus, with a heating pad and a stirrer underneath it. In a 100
ml round bottom flask (RBF), add 0.4 g of H-K-OMS-2 and 1 mmol of the alcohol (9fluorenol). Then add 10 ml of the solvent toluene into the 100 ml RBF and analyze the
reaction with thin layer chromatography (TLC) at zero time. Use 30% acetone in
hexanes to elute TLC silica plates. Reflux and stir reaction at about 100℃ for 20
minutes. Check reaction for completion after the 20 minutes with TLC. If the reaction is
not complete, let it reflux and stir for another 5 to 10 minutes. Once the reaction is
complete cool it to room temperature and then filtrate the catalyst using gravity filtration
and wash it with small amount of toluene. Save the catalyst and remove the solvent by
using a rotary evaporator. Once the solvent is gone, all we have is crude product,
record the crude product’s mass. Recrystallize the crude product from ethanol or
ethanol/water. Record the mass of the recrystallized product and its melting point.
*OMS-2 is a 2x2 octahedral, porous molecule that has square channels that are 4.6Å
across.