Questions tagged [reaction-mechanism]

The detailed (and as complete as possible) description of plausible or observable pathways leading from reactants to products of a chemical process. This tag should be applied to questions about these processes. It may be applied to hypothetical and/or proposed mechanisms.

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4
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1answer
224 views

Rate of dehydration for butan-2-ol and butane-2,3-diol

A question taken from a test series (Vibrant, India): Amongst butan-2-ol and butane-2,3-diol, which has higher rate of dehydration? The carbocation formed in butane-2,3-diol is more stable as it ...
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36 views

Solvent shell collapse

In "advanced organic chemistry part A" book page:306&307 , the author uses the term 'solvent shell collapse' when talking about the reason for retention of conformation in tertiary ...
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2answers
123 views

Role of intermediate in determining the exothermic or endothermic nature of reaction

I was given a question to answer: Which of the following reactions is “not” exothermic? $\ce{CH3-Cl + CH3-CH3 -> CH4 + CH3-CH2-Cl}$ $\ce{CH3-Cl + (CH3)3-CH -> CH4 + (CH3)3C-Cl}$ $\ce{CH3-Cl + ...
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43 views

Reactivity comparison between benzaldehyde and acetaldehyde [duplicate]

One of my teacher says that $\ce{Ph-CHO}$ is more reactive than $\ce{CH3-CHO}$ in performing nucleophillic addition reaction because $\ce{—Ph}$ is planar and thus offers less steric hindrance as ...
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1answer
78 views

Reaction to form amino acid

$$\ce{CH2=CH-CH=O ->[CH3SH][(1,4 addition)] Product (P_1) ->[(i) NaCN][(ii) NH3\\(iii) H3O+] Q_1}$$ Correct statement regarding $\ce{Q_1}?$ $\ce{Q_1}$ is essential amino acid $\ce{Q_1}$ is ...
4
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1answer
137 views

How do I prepare 2-(3-azido-3-oxopropoxy)ethyl methacrylate from methacrylic acid?

I am having some trouble finding a proper synthesis route for the following product. Originally, I was thinking of reacting methacrylic acid with a large excess of ethylene glycol (along with an acid ...
4
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3answers
429 views

Dehydration of primary alcohols without a β-hydrogen

What happens in dehydrations of primary alcohols (in presence of acid catalyst at high temperatures) which don't have a β-hydrogen? For example, in the case of neopentyl alcohol, will it dehydrate as ...
2
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1answer
67 views

Leaving Group Tendencies in Amide Hydrolysis

When we do hydrolysis of amides in basic conditions, we come across a mechanism in which the $\ce{OH-}$ ion attacks the carbonyl forming an intermediate as given in the photo: When the carbonyl gets ...
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81 views

What will be the major product when conjugated alkene (like 1,3-butadiene) is reacted with HBr in presence of R2O2?

What will be the major product when conjugated alkene (like 1,3-butadiene) is reacted with $\ce{HBr}$ in the presence of $\ce{R2O2}$? As we know, two products are formed when no $\ce{R2O2}$ is used ...
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1answer
65 views

Silver “polish” with aluminum foil left a hard yellow coat [closed]

I cleaned my silver teapot with the aluminum foil-baking soda-hot water method. Usually this works well on my silver plated flatware. However, this time it left a hard yellowish coating. I was only ...
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Cleavage of C-C bond in 1,2-diketo compounds with periodic acid

Today we learned the Malaprade reaction in class. My teacher told me that a similar reaction can take place when the substrate is a 1,2-diketo or 1-keto-2-hydroxy or even 1-hydroxy-2-amino(in presence ...
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1answer
394 views

Beckmann rearrangement v/s dehydration of Oximes

In the above question, A is an oxime, which is then reacted with phosphorus pentoxide. Now, phosphorus pentoxide is both a dehydrating reagent and a reagent used for Beckmenn rearrangement, but which ...
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2answers
215 views

Mechanism of conversion of Cr from FeCr2O4 (chromite)

The basic steps involved in the conversion of $\ce{FeCr2O4 -> Cr}$ involves, $$\ce{FeCr2O4 ->[NaOH / air, \Delta] Na_2CrO4 ->[C, \Delta] CrO3 ->[Al, \Delta] Cr}$$ Basically, I'm having ...
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2answers
74 views

Process of a substitution reaction

In this question I am not able to decide by what process this reaction is happening. I first thought that one of the $\ce{H}$ from $\ce{CH3}$ will depart $\ce{Br}$ from $\ce{CBrCl3}$ but I am wrong. ...
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1answer
92 views

Reactants used for manufacturing of mustard gas [closed]

A compound 'X' which is used in manufacture of mustard gas reacts with (ozone) $\ce{NH4Cl}$ to form 'Y' and elemental sulfur ($\ce{S}$). The compound 'Y' reacts with $\ce{NaOH}$ and $\ce{Ag}$ in ...
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1answer
577 views

What happens on heating an ester?

While solving a few questions a came across a problem which asked me what would happen when sec-butyl ethanoate was heated. I had never read about this reaction before and took to researching through ...
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92 views

Mechanism of alkaline hydrolysis of cyclic amide

In this mechanism, I got a pretty different mechanism from the solution. From the model answer, there is an intramolecular proton transfer just before the formation of the carboxylate ion. However, in ...
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2answers
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What happens when an alkyne reacts with ammoniacal Cu2Cl2?

My text book provided me with 2 reactions concerning alkynes (Specifically Terminal Alkynes). The first one was the dimerisation of an alkyne on passing it through ammoniacal $\ce{Cu2Cl2}$. All was ...
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1answer
79 views

Fries Rearrangement Products

During Fries Rearrangement, oxygen donates its lone pair to $\ce{AlCl_3}$ forming $\ce{-O^+-AlCl3}$. Since this is a strong electron withdrawing group, shouldn't the final product be meta-substituted?
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Isomerization of phosphorylated 2-imino-1,3-dioxalanes into phosphorylated cyclic carbamates

I found a patent dating back to the Soviet Union. The patent number is 256764, and the patent describes the synthesis of phosphorylated cyclic carbamates. Here is a section of the patent, followed by ...
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1answer
197 views

Can pthalic acid or 1,2-Benzenedimethanol be possible products of Cannizzaro reaction of phthalaldehyde?

I know the main product that is ortho-hydroxymethyl benzoate ion but I think that phthalic acid and catechol must be formed also in very small amounts but I am unable to get any confirmation from the ...
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115 views

Kinetics of Sabatier reaction

I am modelling a methanation process in MATLAB, where I have a rate equation for methanation $$\ce{CO2 + 4 H2 → CH4 + 2 H2O}$$ in which I need partial pressure of $\ce{CO2},$ $\ce{H2},$ $\ce{CH4},$ $\...
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1answer
48 views

Ring expansion in cyclo compounds

In the following reaction, why does ring expansion not take place? Mechanism that was the correct one: In the second step when there is a protonated carbon the ring should expand to become 6 ...
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63 views

Maximum distance for intramolecular proton transfer

In this reaction (formation of ester from ketone / aldehyde), intramolecular proton transfer happens, since it can stabilize the formal positive charge by resonance after that. This transfer happens ...
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1answer
38 views

Difference in mechanisms between formation of acetal and enamine

When forming acetal from a C=O group with alcohol, the alcohol will act as a nucleophile and attack twice as the carbon is made very electrophilic twice. I wonder in the last intermediate before ...
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26 views

Acid catalyst choice on reaction of carbonyl group and O/N nucleophiles

For oxygen nucleophiles, e.g. $\ce{ROH}$, when reacting with a carbonyl group to form acetal, the acid catalyst used is protonated alcohol. for nitrogen nucleophiles, e.g. $\ce{RNH2/RR'NH}$, when ...
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1answer
94 views

Preparation of Grignard reagent. Free radical rearrangement

Mechanism of formation of Grignard Reagent $$\ce{R-X + ^.Mg^. ->[\text{r.d.s.}] R^. + ^.Mg+X-} $$ $$\ce{R^. + ^.Mg+X- -> R-Mg+X-} $$ As the mechanism of preparation of Grignard reagent suggests,...
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1answer
98 views

Would any alkene possibly aromatize with proper conditions?

I was reading about 2 specific reactions: polymerisation of alkene and aromatization of alkane (of a sufficient size). I thought why can't, having a condition that favored both these reactions be ...
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1answer
61 views

Reaction of 2,4,6-triaminobenzoic acid in a protic medium and heat

The given answer is (A). At first I thought that it was a simple decarboxylation (due to high heat). But that does not seem feasible at all as the ring has no electron withdrawing groups which ...
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2answers
401 views

ortho/para-Selectivity in the Reimer-Tiemann Reaction [duplicate]

I can't figure out why the dichlorocarbene molecule produced in the Reimer-Tiemann reaction gets attached to the ortho position of phenol. The ortho position is sterically slightly more hindered due ...
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1answer
134 views

Birch reduction of 1,2-Cyclopentanedione and Diketones

This answer given to this problem was that only one of the double bonds is reduced into an alcohol. I think i understand how the double bond is reduced into an alcohol. An electron is transferred to ...
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1answer
377 views

Reaction Of Carbonic Acid With NaCl [duplicate]

I was just wondering if it was possible for anyone to specify what reaction conditions are required for the reaction between $\ce{H2CO3}$ (Carbonic Acid) and $\ce{NaCl}$ (Sodium chloride)? Does this ...
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1answer
73 views

Which will be major and minor alkene formed if E1 reaction occurs on 2-chloro-2,4,4-trimethylpentane?

More substituted alkene should be major product while the less substituted as minor product as it is E1 mechanism. But in my answer sheet it is given reverse, i.e. major as less substituted and minor ...
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95 views

What the product of this reaction?

The reaction is as follows, with (i) being my answer, and (ii) being the correct answer in the book. My question is why is the product (ii) formed here and elimination not favoured here? I think that ...
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1answer
53 views

Do reactions carried out in light always follow free radical mechanisms? [closed]

If light is used in a reaction, is it necessarily a free radical reaction? Or are there some other reactions as well which involve light but don't follow a free radical mechanism?
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Do Cyclohexane-1,3-diones Give Positive Haloform Reactions?

Recently a post appeared on ChemSE asking why cyclohexane-1,3-dione (dihydroresorcinol) 1a doesn’t give a positive iodoform test. Unfortunately, the post was subsequently taken down after several ...
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1answer
70 views

Can elemental silicon react with water at room temperature and pressure? [closed]

Free silicon is not found in nature (in water, it might be present in the form Si(OH)4). So how is Si(OH)4 formed? Is there any possibilities of direct reaction with water?
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Enamine Formation in a Diketone

I am trying to form an enamine, and I was trying to figure out if the following reaction is possible: Would this reaction terminate after the formation of the shown product, or will the other ...
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1answer
94 views

Mechanism for simultaneous reduction of nitro group (into aniline) and aromatic substitution (into benzonitrile) by Ethyl cyanoacetate?

I stumbled upon this paper when I'm trying to look at established protocol to synthesize one of the compounds (compound IIk) mentioned in the paper. Studies on Aromatic Nitro Compounds. V. A Simple ...
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2answers
69 views

Is this a correct way to write a chain reaction?

I don't know much about chain reactions and how I understand them, they are just a series of chemical reactions where the products of the preceding reaction act as the reactants for the succeeding ...
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1answer
446 views

Why does FeCl3 react with carboxylic acid, but not with sulphonic acid in this question?

I was solving a question where I was asked to identify the reagents given in the question which could react with a compound provided. The first compound was methanoic acid. One of the reagents given ...
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1answer
73 views

2 problems with elimination-addition of halobenzene using NH2-

When converting chlorobenzene to aniline, I drew the following mechanism and the book says it is correct, but there are 2 questions that I do not understand: In the 2nd step, I am thinking that it is ...
5
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1answer
253 views

Hydrolysis of (chloromethyl)cyclopropane: Is but-3-en-1-ol a possible product?

This is from one of the practice papers for the JEE , asks for possible hydrolysis products of (chloromethyl)cyclopropane . Product A happens to be due to stability of cyclopropyl methyl carbocation. ...
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1answer
72 views

Why does HF generate a carbocation with an alkene

I was reading of different ways to perform Friedel Craft alkylations. One of the methods I came across involved an alkene in the presence of H+ or a mineral acid like $\ce{HF}$. Here $\ce{H+}$ or $\ce{...
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0answers
136 views

Reaction of Alkyl Halide with Ag2S / Na2S

What does alkyl halides give on reaction with $\ce{Ag2S / Na2S}$? In my book, it is given as $\ce{R-S-R}$ but I am not quite sure as alkyl halide react with moist $\ce{Ag2O}$ to gives $\ce{R-OH}$ and ...
7
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2answers
594 views

Alkylation of benzene

I was solving a question where I had to determine a way to convert benzene into n-propyl benzene. I figured out a way by first performing Friedel-Craft acylation with propanoyl chloride and then ...
8
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2answers
625 views

What is an ambident substrate?

I had to identify whether a few compounds are ambident substrates or not. However, as I did not know the term, I took to googling it, but I could not find any explanation for this group anywhere. I ...
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1answer
46 views

What is the reaction mechanism for this reaction? [closed]

Is it Polar unsymmetrical bond breaking (heterolytic) mechanism?
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4answers
2k views

On heating in the Earth's atmosphere, can magnesium react with nitrogen to form magnesium nitride?

This question is derived from a question asked in my school test. What happens when a magnesium ribbon is heated in air? My first response was the formation of magnesium oxide $(\ce{MgO})$ when ...
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1answer
190 views

What reagents change the time of a chemical clock?

I am doing a research task involving an iodine chemical clock reaction. I need to figure out which reagents in the experiment are responsible for changing the time before the colour change in the ...

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