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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Synthetic steps for the interconversion between aldehydes and ketones
I am learning about carbonyl chemistry at the moment. So far, we have been able to make aldehydes and ketones from alcohols (via oxidizing agents). I can't help but wonder if there is possibly any way ...
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What's the purpose of stirring the mixture at 0 degree and dding NaOH to the organic reaction mixture?
I used to follow the lab protocol without thinking, but I now hope to understand why certain procedures are done.
I am synthesizing dimethoxyacetic acid from methyl dimethoxy acetate(so hydrolysis ...
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1answer
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Synthesis of a weinreb amide from an acid
The following shows the conversion of an acid to a weinreb amide:
It was taken from the IChO 2015 preparatory problem set problem 23. In this two-step synthesis, I am slighly puzzled by the first ...
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How to acetylate a thiol group in general?
I wonder (and have tried to find the answer by searching in synthetic chemistry resources) how do you acetylate thiol (R-SH) groups in general? For example the cysteine-SH group either alone to make S-...
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Finding all Chemical Reactions Given Products and Reactants
Suppose only a set of chemical formulas is given. How can you find all mathematically possible chemical equations whose educts and products are only from this set?
Take e.g. the set $\{ \ce{C, H2, O2,...
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t-Boc protection of amide (urea)
I'm trying to prepare protected urea and I'd like to protect it with some alkali stable PG. Is it possible to protect urea with t-Boc? Or is there another way to get boc-protected urea?
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152 views
What is the mechanism of azulene synthesis?
In the Organic Syntheses preparation of azulene (http://www.orgsyn.org/demo.aspx?prep=CV7P0015) there are two reactions. First is a clevage of the C-N bond in pyridine and the second one is the ...
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1answer
48 views
Preference for basic conditions in ester hydrolysis
It has occurred to me that it is very common see the use of basic conditions for ester hydrolysis in various syntheses. One such sequence commonly seen in the case of the malonic ester synthesis is:
$...
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What takes place in this transformation of the 1,3-dicarbonyl?
I was just looking at a particular synthesis method on the Organic Chemistry Portal when I saw a particularly puzzling step, involving a 1,3-dicarbonyl compound. The step which I am puzzled by is ...
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Monitoring amino acid esterification
I am trying to monitor the esterification of a non UV active amino acid.I used thionyl chloride and Methanol as reagents.
As amino group is unprotected, Ninhydrin should give positive result for both ...
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1answer
59 views
Effect of substituents on Ullmann reaction
This question that I recently encountered asked what the most suitable substrate for the Ullmann reaction would be. The answer given is (b) but I think it has to be (d) as the nitro group acts as EWG ...
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Why might the yield of my synthesis of triphenylmethanol be so poor?
I performed the classic Grignard reagent formation leading into the preparation and purification of triphenylmethanol using phenylmagnesium bromide as my Grignard, and benzophenone as the reagent for ...
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Why is phosphoric acid preferentially used for dehydrating alcohols during synthesis of alkenes?
I have also seen concentrated sulphuric acid being used, but what makes phosphoric acid preferable to sulfuric acid?
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1answer
55 views
Why doesn't self condensation occur in acetoacetic ester synthesis
So, I came across a quite versatile method to synthesize aldehydes and ketones, its called the Acetoacetic ester synthesis.
Suppose I need some 2-pentanone. So to synthesize it via this method I can ...
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35 views
Production of L-glucose
What chain(s) of reactions are used to produce L-glucose? I did a search on Google scholar but to my surprise nothing came up. My guess would be that the synthesis starts from D-glucose for which ...
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1answer
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Opening the imidazoline ring in tolazoline
Hello.
I was studying about the alkaline ring opening or purines. While doing research, i came across this compound. This got me thinking if we can use the same procedure to open the imidazoline ring ...
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Changing the CO2 concentration (adding or subtracting) inside a sealed vessel?
I am looking for a method of modifying the CO2 concentration inside a sealed container that is both precise and repeatable (C02 needs adjustment every time the container is sealed, also need to be ...
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1answer
409 views
ICHO Synthesis Problem 2018
I've several doubts about this ICHO synthesis problem, which was a part of the preparatory problem package of 2018 (so yes, it's not a part of an ongoing contest)
Before sharing the answer given, I'...
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2answers
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Cis Orientation of dienophiles orientation of groups maintained in Diels Alder
When I was reading about Diels-Alder reactions, I was confused about the cis and trans rules for dienophiles, as shown below.
The text told me that "a cis dienophile will generate a ring with cis ...
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1answer
117 views
questions about the synthesis of iodobenzene from aniline
I am conducting an experiment about synthesis of iodobenzene from aniline, referring to this site(and various sites) (http://www.prepchem.com/synthesis-of-iodobenzene/). Below is my experimental ...
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1answer
30 views
Can you make imines from Formaldehyde or Acetaldehyde?
Title says it all. Wondering if imine formation would work with an aldehyde, even better would be formaldehyde.
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Reaction between Salicylaldehyde and 2-Benzoylpyridine
In a paper by Sheng et al (10.1016/j.dyepig.2018.07.036) the authors synthesize the compound MZC as shown in the scheme below.
I'm looking for information about what the reaction mechanism is that ...
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1answer
91 views
How to remove MEHQ from Methacrylic acid monomer without reduced pressure distillation?
I am aware that the standard way to remove MEHQ from Methacrylic Acid is to perform reduced pressure distillation. The papers I see suggest using ~ 10 Torr pressure to perform distillation. Sandler's ...
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1answer
109 views
Can thiols be created using a Grignard reagent?
I'm trying to find information on the synthesis of thiols via Grignard reagents. While looking at the synthesis routes on Wikipedia, it said that a Grignard reagent will react with sulphur to form ...
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305 views
Converting phenol to para-nitrophenol via nitrosophenol
Our class 12 text book says that if we treat phenol with mixture of concentrated $\ce HNO_3$ and $\ce H_2SO_4$, instead of nitration, the ring is oxidized to quinone.
So, the book proposes that we ...
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1answer
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Synthesis of 3-(2-oxocyclohexyl)propanenitrile
Does this seem correct?
The point is to draw the mechanisnm of which 3-(2-oxocyclohexyl)propanenitrile is synthesized from 1-(cyclohex-1-en-1-yl)pyrrolidine.
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1answer
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Formation of (Gamma) Methylparaconic acid
I came across this question recently,
I tried to devise a mechanism but I'm struck here,
My try -
Moreover, I think my mechanism is somewhat inefficient because of formation of some byproducts, ...
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1answer
152 views
Why is ethanol distilled off before adding water?
I am doing a malonic synthesis shown below, and I wonder why I should distill ethanol off before adding water in the first step of the reaction (First I add absolute ethanol and solid sodium).
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1answer
106 views
How to predict ease of oxidation or reduction for a given oxidising or reducing agent? [closed]
I have never understood which agent will be able to oxidize or reduce which type of reactants and yield which type of products will be formed. For example I want to know about DIBAL-H and how is it ...
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1answer
46 views
Predicting products of a reaction and balancing [closed]
2BiOCl + NaOH = BiOH + NaCl.
This is the reaction where I am trying to get Bismuth Hydroxide as one product and salt. My problem is what is the state of Bismuth Hydroxide? Whether it is BiOH or Bi (OH)...
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2answers
319 views
Conversion of oxalic acid to malonic acid
The reagents I have used here are $\ce{LiAlH_4}$ which reduces the carboxylic groups into alcohol.Used $\ce{HIO_4}$ which breaks up the molecule into methanal. Then I applied Grignard reagent which ...
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1answer
290 views
Synthesis of 1-methylcyclopentene from cyclopentene
I have to put a methyl group on a cyclopentene. My teacher made this solution (the picture). But my first guess was just to use $\ce{CH3Cl}$ and $\ce{AlCl3}$. Why can't you do that?
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1answer
383 views
Ortho vs para alkylation of chlorobenzene
I have a question to the solution regarding the product formed in a reaction with chlorobenzene with the use of (i) $\ce{CH3CH2Cl}$ and (ii)$ \ce{AlCl3}$. Since the -Cl substituent is ortho- para-...
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0answers
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P2NP synthesis ammonium acetate catalyst?
I am going to try to prepare some P2NP from benzaldehyde and nitroethane following this procedure:
The aldehyde (5g), 5 ml. of the nitroalkane, and 2g of ammonium acetate were added to 20 ml of ...
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1answer
54 views
Sephadex and purification of products [closed]
Sephadex is useful for the separation and purification of many natural products.
Is it also useful for the separation and purification of artificial chemicals (in organic synthesis ) or not and why ?
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1answer
221 views
Malic acid 3-step synthesis
I was quite puzzled by the answer for this question in my Carboxylic Acids and Derivatives tutorial question set. It is question 6 (a), on the synthesis of malic acid, as shown in the image below.
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1answer
470 views
What happens to the methanol formed by the hydrolysis of methyl 2-hydroxybenzoate (oil of wintergreen) when synthesising salicylic acid?
Here are the reaction equations for reference (you may recognise this as a preliminary step for the synthesis of aspirin).
Steps for synthesis of salicylic acid:
1) methyl 2-hydroxybenzoate + sodium ...
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1answer
455 views
How to acid-wash sand?
I need some acid-washed sand to smooth out boiling in diethyl ether synthesis. I aready have pre-washed sand for general filtration purposes, but it is not labeled as acid-washed.
Unfortunately, I ...
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1answer
248 views
Evaporation of concentrated formic acid and semi-concentrated sulfuric acid at room temperature
I recently looked at a reaction where CO is synthesized using formic acid and sulfuric acid, which seems to be one of the easier to control reactions for this, and obviously ventilation etc is ...
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How can I solve this synthesis?
I have this task to do:
My solution:
Is that possible? Can you please help me with the steps 2 and 3?
This is what I did, but my teacher told me I should make the diketone (compound no. 5) from ...
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2answers
511 views
If acyl chlorides are reacted with aqueous ammonia, will carboxylic acids also be formed?
As part of my A-level chemistry course, I have been taught that an acyl chloride will react violently with water to produce a carboxylic acid and hydrochloric acid. I have also been taught that an ...
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1answer
411 views
Understanding the synthesis of twistane [closed]
What are the products P and Q?
This was a question in my test series, but I don't have any experience with bridge head compound regarding the cis and trans transformation. I need help understanding ...
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1answer
157 views
In a two electrode system, is the applied current density referring to just the working electrode or to the auxiliary electrode as well?
I'm doing an experiment electrosynthesizing a polymer using a two electrode cell and it says to do it under 0.5 mA/cm^2. However, I am unsure if that means 0.5 mA per square centimeter of surface area ...
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1answer
91 views
Methylnitrobenzene ring formation Synthetic Route
I know the malonic ester is probably used to make propanoic acid or some carboxylic acid, and then joined to the methylnitrobenzene. But I just can't figure out what glues to the methyl. I know the ...
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1answer
56 views
Bridged ring system reduction through Wolf Kisher: Is it possible?
Is it possible for a ketone like this to undergo the Wolf Kishner mechanism? If so, what would be the product? It seems unlikely to me as disrupting the stable equitorial carbonyl seems unfavorable......
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How to synthesize tetrabutyl titanate from titanium dioxide powder?
How do you synthesize tetrabutyl titanate $(\ce{[CH3(CH2)3O]4Ti})$ from titanium dioxide ($\ce{TiO2}$) powder? As I know, we can get $\ce{TiO2}$ from tetrabutyl titanate, but how can we do the ...
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Nucleophilic Aromatic Substitution in ring with 4 Substituents
Does the chlorine still get substituted by OH in this case?
I was also wondering, if it does get substituted, does anything happen between the ethanol substituent and the phenol -OH? I'm suspecting ...
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2answers
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HCl/H2O with alkene: Which one reacts?
I think that the initial step forms a tertiary amine, which then in the presence of the ketone and trace acid undergoes nucleophilic addition. But then, for the $\ce{HCl/H2O}$ in the last step, which ...
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4answers
107 views
Chlorinating specifically one carbon on a symmetrical alcohol
The final target molecule is 1-chloro-2-amino propane.
The amination step would be simple via reductive amination of 1-chloro-iso-propanone.
Obtaining 1-chloro-iso-propanone would be from ...
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1answer
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Biodiesel synthesis
I want to do the synthesis of biodiesel with the cooking oil (it contains colza and sunflower oils) in ethanol and KOH. After 1 hour of reaction, I let the solution to rest for 3 days.
At this stage,...
