Questions tagged [synthesis]
Synthesis is a purposeful execution of chemical reactions to obtain the desired product. Applies to long and complex natural product syntheses as much as to short one or two-step syntheses. This also covers synthetic problem sets and retrosynthetic analyses.
849
questions
0
votes
0
answers
21
views
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
votes
0
answers
57
views
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
views
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 ...
- 383
1
vote
0
answers
28
views
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
views
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
vote
0
answers
31
views
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
views
(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 ...
- 799
4
votes
1
answer
107
views
Compatibility of DCM/CCl3 with sodium hydride
In our undergraduate studies we were told that chlorinated solvents should not get in contact with alkaline elements like sodium, potassium etc., due to the violent reaction that will form the ...
- 799
1
vote
1
answer
92
views
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 ...
- 113
5
votes
2
answers
131
views
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
vote
0
answers
56
views
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 ...
- 47
1
vote
0
answers
34
views
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,...
- 41.2k
2
votes
0
answers
31
views
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
0
votes
0
answers
33
views
Synthesis of polypropylene
So, I have two questions regarding the synthesis of polypropylene:
I have tried looking everywhere but couldn't find a detailed mechanism for the termination step of the synthesis of polypropylene (...
- 31
5
votes
2
answers
197
views
Synthesizing Cyclotetrazane from Hydrazine and Diazene?
Could cyclotetrazane — a compound with nitrogen atoms arranged in a square configuration — be synthesized? A hydrogen atom would be bonded to each vertex (nitrogen atom):
Could cyclotetrazane be made ...
user145192
2
votes
0
answers
50
views
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
votes
0
answers
35
views
Electrophilic fluorination power: selectfluor vs NFSI
I want to fluorinate the methylene hydrogens between an aryl group and a phosponate ester. The reaction is similar (not identical) to this one:
For some reason on the literature people are using very ...
- 799
2
votes
0
answers
71
views
Could a de-commissioned synthetic ammonia plant be adapted for use in removing CO2 from the atmosphere (DAC)?
I was prompted to ask this question by viewing a disused $\ce{NH3}$ plant in the harbour near where I live.
Like many it functioned using a methane feedstock from a natural gas find off the coast. I ...
- 29
4
votes
0
answers
100
views
With two reagents common on Mars, fluorite and CO2, how would I produce carbon tetrafluoride?
The hypothetical terraforming of Mars would require the heating of the atmosphere. A commonly suggested method is the in-situ production of fluorocarbons, powerful greenhouse gases.
For example, ...
- 141
2
votes
0
answers
37
views
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
votes
0
answers
50
views
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 ...
- 161
1
vote
0
answers
32
views
Why does hydrogen peroxide decompose during the oxidation of an aryl amine to and nitroarene (rt) and what are the possible overoxidation products?
Small scale:
I attempted the oxidation of an aryl amine (2-amino-6-bromonaphtalene) to the nitroarene using hydrogen peroxide (ArNH2, H2O2, MeCN (15 mL as solvent). After trying it on small scale (0.1 ...
3
votes
0
answers
50
views
What is the difference in reactivity between the various borates (trimethyl, triethyl, triisopropyl borate) to form boronic acids?
For the transformation of 1,3-dibromobenzene to bromobenzene boronic acid, different groups use different boration reagents namely trimethylborate, triethyborate and triisopropylborate).
The reaction ...
0
votes
0
answers
39
views
Need Suggestion for Picking the Right Solvent for Column Chromatography
I've completed my reactions, and based on the stoichiometry and TLC analysis, I think my mixture should contain 3-4 compounds:
Ethyl gallate (my product)
Gallic acid (the reagent/starting material)
...
- 155
4
votes
0
answers
273
views
Exchange of Fluorine to Oxygen for Fluorophosphonic acid by silylating agents or other methods?
[Warning, long post!]
Dear all,
I am confronted with a seemingly easy transformation. I want to remove a fluorine atom at a fluor phosphonic acid salt. The usual method to achieve this is the basic ...
- 799
1
vote
1
answer
124
views
How does the following cyclization reaction work?
The following is a reaction from a school provided lab manual. However, I am unable to find anything similar to the cyclization reaction taking place. All of the reactions I have found online make use ...
- 49
2
votes
0
answers
32
views
TMSBr and 2,4,6 Collidin in Acetonitrile leads to white precipitate
I want to hydrolyse a phosphonic acid ester with TMSBr.
I think this reaction works only with the addition of base. Without base, the product in my specific case is prone to deterioation due to acid ...
- 799
2
votes
0
answers
41
views
What is this gel byproduct of acetylsalicylic acid recrystallization?
I did a very simple acetylsalicylic acid synthesis from salicylic acid and acetic anhydride (with phosphoric acid as a catalyst). After rinsing, filtering and drying the product I dissolved it in ...
- 31
2
votes
0
answers
151
views
Removing DCC and its by-product from Steglich Esterfication
In my small research, I want to synthesize 3 alkyl gallates (ethyl gallate, butyl gallate, and hexyl gallate), and here's my overall reaction using Steglich esterification):
However, from reading ...
- 155
7
votes
2
answers
642
views
Question about the differences of white and grey NaH properties
We are having some problems with the next reaction in our lab. As you can see, is the sulfonylation of an indole in which we use NaH (60% dispersion in mineral oil) as a base. This reaction goes with ...
- 81