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.
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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 ...
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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 ...
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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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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 ...
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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 ...
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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 ...
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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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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 ...
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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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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 ...
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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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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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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(...
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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 (...
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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 ...
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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/...
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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 ...
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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 ...
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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, ...
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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 ...
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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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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 ...
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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 ...
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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)
...
4
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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Hydrolyse a fluorophosphonic compound / Which protective group strategy can I use for phosphonate esters to access the free acid after a reaction?
I have a synthetic problem in my PhD thesis, in which I synthesize a phosphonate ester.
To be more precise, it is a phosphonofluoridic compound. In my specific case, the fluorine attached to the ...
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Steglich Esterification in Alkyl Gallates
Based on my research (reading some articles), some alkyl gallate syntheses used Steglich esterification instead of the usual esterification (Fischer esterification). The reason why Steglich ...
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2
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Should I remove inhibitor from methyl acrylate?
I need to run multiple aza-Michael additions of methyl acrylate with various amines (dimethylamine, benzylamine, phenylethylamine, aniline, etc.) in order to get the bis-ester. I was wondering if the ...
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Breakdown of addition polymers
We know that condensation polymers can be broken down by hydrolysis with the elimination of small water molecules.
Then what about addition polymers? How can they be broken down into their monomers?
I ...
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Synthesizing "Methyl 2-(2-oxopyrrolidin-1-yl)-2-phenylacetate" [closed]
I am a chemistry student, here I mapped out the steps one might take to synthesize Methyl2-(2-oxopyrrolidin-1-yl)-2-phenylacetate, a piracetam dirivitive. Please add any steps I might be missing and ...
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Advise on performance vs cost of the Berkland-Eyde Process for direct synthesis of Nitric Acid from atrmospheric air
I am new to chemistry, having gone down an electronics route in my career, so I decided to pick up where my 'O' levels ended (many years ago) and make a better understanding of the topic a sort of ...
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Methanisation in the Haber Porcess
I've been reading up on the Haber process lately.
In one such industrial case of ammonia synthesis, hydrogen is created through steam reforming, which creates some carbon monoxide. As the reaction ...
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What is the product and mechanism of reducing a cyclohexanone derrivative with LAH?
I've been trying to figure out the product and mechanism of the reaction pictured below for a while now:
I'm fairly sure that the first step is the reduction of the ketone by LAH, which results in a ...
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Hydrolyse Phosphonate diester to free phosphonic acid under relatively mild conditions?
I want to hydrolyse a phosphonic acid diethylester to the corresponding free phosphonic acid. In the literature, it is described, that usually strongly basic or acidic conditions are utilized to ...
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Why did this synthesis of Aspirin fail?
I tried to synthesize acetylsalicylic acid(aspirin) by the method below. However, I definitely failed and got something unknown.
The method used was:
Add 2.5 g of salicylic acid(about 2494 mg), 3.0 ...
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Production of sulphuric acid
To my knowledge, sulphuric acid is produced by complex industrial processes like contact process.
The following structure shows a sulphate ion.
I wonder why sulphuric acid cannot be produced through ...
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Reduction of benzylic alcohol and halide using H2 and Pd
I am studying drug synthesis, and I found some examples that uses $\ce{H_2}$ and Pd/C or Pd/$\ce{BaSO_4}$ as catalytic hydrogenation reagents for reduction of alcohol or halide in benzylic position. ...
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Degradation of 4-MeO-Tetrahydrocarbazole
I recently synthesized 4-Methoxy-Tetrahydroxarbazole from 4-MeO-Phenylhydrazine and Cyclohexanone. The product had a off-white color directly after synthesis but was brown after standing over night at ...
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Synthesis of 1-ethylcyclohexane-1,2-diol from cyclohexylethene
Here's my synthesis:
HBr
NaEtO
OsO4/NMO
But the problem is that for step 2, there are 3 possible alkene locations, with all of them having 3 substituents, so I would have all 3 forming (although 2 ...
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Find the missing chemical structures in the reaction sequence
I came across the following question, where a set of reagents are used, starting from a carbohydrate derivative.
I understand that this is some total synthesis reaction, but I cannot find which one.
...
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Selective formation of enolates
I saw the following reaction on Modern methods of Organic Synthesis by Carruthers. The reaction is about the selective alkylation of trimethylsilyl enolates, and is shown below.
However, I have some ...
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Amidine synthesis from nitrile and dimethylamine using n-Buli as a base
I am making LiNMe2 using n-Buli (5.5 equiv.) and dimethylamine (5.0 equiv), -15 ºC, dry THF and under nitrogen atmosphere.
I have been doing the reaction and I can observe conversion of starting ...
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3
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Can any compound form into an amorphous solid?
I am curious whether it is possible or not to make any solution of a specific compound into a crystal lattice or into an amorphous solid? I know that crystals form under specific conditions but seem ...
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TMSiBr and Oxalylchloride for ester cleavage
I am wondering what is the advantage of using TMSiBr do perform an ester cleavage in comparison to perform chlorination first for example with oxalylchloride or thionylchloride and than add water?
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Esterification of phosphonic acid chloride is working with isoprenol but not with prenol
I am performing an esterfication reaction between an activated phosphonic acid (chloride) and a series of alcohols. Until now, I was not able to make the reaction work with prenol, while isoprenol is ...