| Wednesday and Thursday research |
[Dec. 10th, 2006|05:00 am] |
I removed the solvent of the azine we made. Because I wasn't trained to run the NMR machine, I had to give the sample to the grad student and he ran it on Friday. I did not go into the lab on Friday, so I do not know how it goes. I will find out about it on Monday.
Aside from that, the phenyl phosphine we ordered from China has finally arrived. We then set up the reaction of this phenyl phosphine with the hydrazine monohydrate under Nitrogen. The phosphine smells really bad. The box it came with even smell really bad too. I wish all of you can smell it too, so that you all know how bad it is. After adding them together, I left the reaction to run overnight. Over the weekend, I am working on the poster for the poster session on Monday. I'm looking forward to see everyone's. |
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| Update on my research |
[Dec. 6th, 2006|01:21 am] |
So, last week and this week I tried to run the reaction again. As I said before my research is looking at synthesis of 3,4-diazaphospholanes using two different routes. The first route was to react a primary phosphine with aqueous formaldehyde, followed by hydrazine. The second approach was to make an azine from an aldehyde and hydrazine before reacting it with a primary phosphine.
The first path failed because instead of producing 3,4-diazaphospholane, we got two-five membered rings of phospholane based on NMR spectra. We couldn’t try this reaction again as we are out of the reagent and it is still on its way from China (I believe). It’s been three weeks now. Because of that, I ran the reaction as shown in the second path. However, before running the reaction itself, I had to purify the isobutyraldehyde by distillation because the chemical looked really old and NMR taken shows a lot of impurities. After running the reaction overnight, the intermediary product was obtained, but again there are some impurities. Therefore, I had to run a column to purify it before reacting it again.
Today, I ran the column and took 52 fractions. Based on previous column experience, I found that there are three different products (two of which are unwanted) eluting from the column. That’s why I collected that many fractions. Tomorrow, we will run the NMR and hopefully it will be pure enough that I can proceed to the next step, reacting the intermediary product further to make 3,4-diazaphospholane, I hope. |
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| Research Continuation |
[Nov. 25th, 2006|03:24 pm] |
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So, we found out that neither of the NMR shows a strong present of the product we desired. There were still a lot of impurities and thus, we decided to purify the isobutyraldehyde we are using by simple distillation on Wednesday. Because of the break, I haven't been able to go into the lab yet. However, when I go in on Monday, we should be able to re-do the reaction with a purer reactant.... Time really flies!! |
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| Independent Research |
[Nov. 17th, 2006|03:33 am] |
Since the last time I posted, I have done many things. First, I reacted the product I got from the first reaction (cyclohexylphosphine and formaldehyde) with hydrazine. We were hoping to get 3,4-diazaphospholane by adding the hydrazine dropwise. The method was proposed to avoid a further hydrolysis of the hydrogen from nitrogen, which was the result of the paper from which the reaction is based on. Upon taking the mass spec of the product, however, we found that the unwanted product was still made instead of the 3,4-diazaphospholane.
Because of that, we tried another route of using chiral aldehyde. In this case, we chose isobutyraldehyde and reacted it with hydrazine. The solvent used for the reaction is ethanol and the reaction was stirred overnight. Then, the solvent was removed using a rotary evaporator and an NMR spec was taken. The NMR spec shows that there are a lot of impurities in the product that we made. So, today I ran a column to purify the product using DCM as the solvent. It was found using TLC that there are 2 compounds present in the product. Running the column resulted in the separation of the two product and fractions were collected (I collected a total of 47 fractions!!!). Solvent will be rotavaped tomorrow and we will see how the NMR spec looks like this time to determine which of the two compounds is the product. |
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| Independent Research Lab |
[Nov. 7th, 2006|01:42 am] |
So, for the second part of this class I am working in the Landis group. My project is a small part of a bigger project, which is Asymmetric Hydroformylation of Enamides. The objective of the project is to make 3,4-diazaphospholane ligands that are enantioselective.
So, I've been to the lab twice so far and it has been really interesting. All of the reactions that I am running have to be oxygen free and I have been shown around on how to deal with this. We have this big bad where things are put under nitrogen gas and if I need to get something out of it there are quite a number of steps to avoid the contamination of oxygen.
Last Monday, I started the first reaction. Cyclohexylphosphine was reacted with formaldehyde in ethanol solvent. The reaction was left overnight and actually once everything's added, the reaction can be left unattended. Most of the works come from setting up. First I had to degass all the reactants and reaction glassware. Everything went pretty well and I am psyched to go back into the lab tomorrow to continue working on my project. More updates on tomorrow's lab will come shortly. |
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| Catalyst Synthess and Enantioselective Epoxidation |
[Oct. 29th, 2006|04:12 pm] |
Last Monday, we inserted the metal to our Jacobsen ligand and everything went pretty smoothly. We were supposed to use polarimeter to check the optical rotation of our ligand, but it was broken. As a result, we had to skip it. The melting point of the catalyst was found to be 342 degrees. It was a little higher in comparison to the reference melting point.
Then, on Wednesday, we did the enantioselective epoxidation with the catalyst we made earlier. I used styrene as the alkene and the reaction proceeded faster than I had expected. The procedure said the reaction would be completed in two hours, but my reactants were all gone in under an hour as checked by TLC. Then the epoxide was filtered and it was saved for Monday to be purified by flash column chromatography. |
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| Ligand Synthesis - (R,R)-N,N'-Bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine |
[Oct. 22nd, 2006|02:36 pm] |
That's a very long name. Let's just refer it as the Jacobsen Ligand. So, last Wednesday we synthesized our Jacobsen ligand. Everything went smoothly and we obtained the yellow solid. The melting point of the product was found to be 197 degrees C, which is only 3 degrees lower than the reference melting point of 200 degrees C. The experience at the lab on Wednesday was quite satisfying because we did not screw up. That gave me such a relief!
Also on Wednesday, all of us who are taking the 2nd credit option got assigned to the professor whom we will be working for on the special project thing. I emailed the professor and have yet to receive a reply. To be honest, I am kind of nervous about what to expect and what kind of project will I be getting. I guess, I won't know until he gets back to me.
Anyway, tomorrow we will check the polarizability of our Jacobsen ligand and then insert Mn into it to make our catalyst. Seems like it will be a long lab period because we are required to heat things up several times for either 30 minutes or 1 hour. Hope things will go well. |
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| Interesting Natural Product |
[Oct. 18th, 2006|01:59 am] |
I like spicy food and I found that the active component in chili pepper that produces the burning sensation is a type of organic compound - Capsaicin (8-Methyl-N-vanillyl-6-nonenamide).
This molecule is non polar and therefore, drinking water to reduce the burning sensation is actually ineffective. The reason for this is because capsaicin is unable to dissolve water, so instead it spread the burning across the surface of mouth.
Another interesting thing about capsaicin is that it can be used to temporarily relieve minor aches and pain of muscles and joins. Capsaicin can also be used to deter pest. So, from now on, eat more of those HOT chili pepper.. =) |
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| End of Piperine Purification and Start of Epoxidation |
[Oct. 18th, 2006|12:52 am] |
So, isolating nnd purifying of the piperine from black pepper was not really that bad. It's worse, especially when I had to redo my column because I didn't pack it properly. It was frustrating, but I finally got it to work and I am quite proud of my accomplishment. Thanks to Teshik and Chris who had been helping me throughout the lab. Now, I should be able to run a similar column better =)
Anyway, last Monday we started the epoxidation reaction. Everything went fine. I hope it'll be this way for the rest of the experiment. I wish! |
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| Synthesis of Piperine |
[Oct. 8th, 2006|01:41 pm] |
So, on Wednesday we continued the synthesis of piperine after it was being refluxed for 40 hours. Turned out, it was not very hot after all. The precipitate that was first collected was a yellow solid instead of beige powder as obtained by the other two groups. When we tried to recystallize it, no crystal was formed. We tried rotavaporized it and re-added the ethyl acetate + hexane. No such luck. So, we put a parafilm on the flask and we will see what happens tomorrow. Unsuccessful synthesis can be quite frustrating. I really don't know what to say and can't really think of what errors have been done in this process.
Anyway, I'll just have to wait until tomorrow. Plus, tomorrow we will isolate piperine from ground black pepper, which should be interesting. |
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