All Questions
Tagged with synthesis organic-chemistry
572
questions
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24
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Bromination with NBS and AIBN
I reacted 3-pyridylacetic acid (6 fluoro) with NBS and AIBN in CCl4. I refluxed the reaction mixture for 4 hours at 80 degrees. No reaction occurred, and the starting material remained (based on TLC ...
- 47
2
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0
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57
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Clean *di* protection of phosphonic acid dichloride with a suitable protection group with clean deprotection
For some time I am struggling with a tricky synthesis problem in my pHD. I think I came closer now, but I still need a link in the chain to make my idea work.
The principle goal here is access a free ...
- 799
9
votes
3
answers
551
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Synthesis of racemic nicotine
In my advanced organic chemistry course, we were asked to fill the following scheme for the synthesis of racemic nicotine, starting with ethyl nicotinate:
Exercise 6: Complete the following scheme ...
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1
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28
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How to avoid side reactions when making boronic esters (Homocoupling, Hydrogen specie)?
I have been working with suzuki couplings using substituted naphtalenes (typically 2-bromo-7-R-naphtalene) for a while now, and making the boronic specie is always a pain.
I can't make the boronic ...
3
votes
1
answer
180
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Will a nitro aryl resist an halogen exchange using nBuLi?
I would like to boronate 2-bromo-6-nitro-naphtalene using nBuLi and quenching with 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane. Since there is no alpha proton to the nitro, and that the nitro ...
1
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0
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31
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After adding the electrophile (BOMe3) in an halogen exchange (nBuLi) reaction, why do we leave the reaction stir overnight?
Very basic question.
In all the procedures for halogen exchange reactions reported using boronic compounds, the reaction is left to run ON at room temperature after addition of the boronic specie.
In ...
2
votes
1
answer
60
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(Di)chlorination of phosphonic acid ester
What is the best way to do this reaction to form the dichloride as an reactive intermediate when the substituent R is acid sensitive?
In the literature the reaction is either performed with PCl5, a ...
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1
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1
answer
92
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Are there methods of synthesizing rubber from plant materials?
First and foremost, I am not talking about natural rubber. I am asking if there are any industrially used methods of synthesizing rubber from agricultural products as opposed to synthesis of rubber ...
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5
votes
2
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131
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Synthesis of (S)-2-hydroxy-4-oxohex-5-enal
I am currently working on a total synthesis strategy, but I was told that a key step in my total synthesis probably wouldn't work, so now I am trying to figure out a way around it. The compound that I ...
1
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0
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56
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Quenching reagents for specific reaction
A reaction general procedure is given as follows:
A mixture of 2-fluoro-5-iodo pyridine $(\pu{1.0 mmol})$, methyl
acetoacetate $(\pu{3.0 mmol})$, $\ce{CuI}$ $(\pu{10 mol\%})$, $\ce{K3PO4}$ $(\pu{3.0 ...
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34
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Synthesis of 1-phenyl-2-buten-1-one using an aldol condensation
I asked my students to suggest a route of synthesis for 1-phenyl-2-buten-1-one [1], using a Claisen or aldol condensation. One student had the idea of forming the aromatic ring as part of the reaction,...
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2
votes
0
answers
31
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What is the purpose of chloromercuration of HgOAc group?
In some reactions using $\ce{Hg(OAc)_2}$, I saw some cases that convert $\ce{-HgOAc}$ group into $\ce{-HgCl}$ group by adding $\ce{NaCl}$. Below is one example, the synthesis of (+)-preussin.
Mercury(...
- 1,101
2
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0
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50
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Palladium coupling reactions and purification
I tried to synthesize 2-(6-fluoropyridin-3-yl) acetic acid from 5-(Chloromethyl)-2-fluoropyridine using Pd(OAc)2/PPh3 catalyst,Na2CO3 and DCC. I eluted my product on TLC with Ethyl acetate/hexane/...
- 47
2
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37
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Synthesize pivaloyloxymethyl ester, but with a substrate that is a terrible nucleophile
I want to synthesize an pivaloyloxymethyl ester from a fluorophosphonic acid. The idea is, to make a compound cell permeable that than be cleaved in the cell by enzymes. Apparently, the acid is a very ...
- 799
4
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50
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Why cool a reaction down when adding reagents if you're only going to reflux subsequently?
I've seen several procedures using thionyl chloride (SOCl2) to make an ester, where the first step is to add the thionyl chloride to the reagent/solvent on ice or subzero temperature, followed ...
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