21 votes
Accepted

Selective nitro reduction of poly nitro compounds

Is there any way to predict which nitro group will be reduced After having gone through three pages of Google Scholar and reading several research papers looking for an answer, there is definitely no ...
Gaurang Tandon's user avatar
16 votes

Acidity order of nitrophenols

You have correctly identified that m-nitrophenol should be the weakest acid among the isomers as the resulting anion cannot be stabilised by the $\text{-M}$ effect of nitro group owing to its meta ...
Archer's user avatar
  • 5,453
15 votes
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What is the significance of the 2 and 4 positions in 2,4-DNP?

Probably any DNP could work if you could get it. But, because of the directing character of substitutents in electrophilic substitution you inherently favor the 2,4 isomer: the hydrazine group (or ...
Oscar Lanzi's user avatar
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13 votes

Are groups other than carbonyl reduced by Clemmensen reduction?

I would look at it in the following way: The oxidation state of the carbonyl carbon is +II, while the oxidation state of the nitrogen in the nitro group is +III. So nitrogen is in a higher oxidation ...
logical x 2's user avatar
  • 2,794
12 votes

Most favorable position of attack of an electrophile on 4-trifluoromethyl-1,2-diphenylbenzene

This is an another way to answer the question: On the way, I also want to show OP that why central ring bearing $\ce{CF3}$ group has the highest electron deficiency at ortho- and para-positions (...
Mathew Mahindaratne's user avatar
10 votes

Most favorable position of attack of an electrophile on 4-trifluoromethyl-1,2-diphenylbenzene

TL;DR - The ring with positions 1, 2, and 6 on it is more deactivated than the ring with positions 3, 4, and 5, so the correct answer cannot be position 2 (as marked) or positions 1 and 6 (as you ...
Ben Norris's user avatar
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10 votes
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Why is the ortho product major in the nitration of anisole with nitric acid and acetic anhydride?

It is complicated, as this paper from Olah et al. here shows, but this passage offers a possible explanation: With the reactive nitronium salts, the isomer distribution of the nitration of anisole ...
Waylander's user avatar
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9 votes
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Why does a mixture of nitrous acid with concentrated nitric acid cause nitration of benzene instead of nitrosation?

You were absolutely correct when you said that nitrosation takes place. What actually happens is that after nitrosation occurs, concentrated $\ce{HNO3}$ oxidises the nitroso group to form ...
Avyansh Katiyar's user avatar
9 votes
Accepted

What products do 4-nitrobenzaldehyde and 3-nitrobenzaldehyde give in a crossed Cannizzaro reaction and why?

The first thing to point out is that the products of the Cannizzaro reaction do not necessarily correspond to the most stable products, i.e. the reaction is not necessarily thermodynamically ...
Jan's user avatar
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9 votes
Accepted

What compound was drawn on this sidewalk?

Certainly, it's meant to be trinitrotoluene, TNT, with a "typo". Perhaps a craftsman tried to copy an image, such as that from Wikipedia, below, which shows the oxygen atoms outside the ring:...
DrMoishe Pippik's user avatar
8 votes

Selective nitro reduction of poly nitro compounds

Zinin reduction was discovered by a Russian organic chemist Nikolay Zinin in 1842 (Wikipedia) and revieved by Porter (1973; Ref.1). As pointed out by @Gaurang Tandon and @Nilay Ghosh in their answers, ...
Mathew Mahindaratne's user avatar
8 votes
Accepted

Reaction of an alkyl halide with silver nitrite

On treating ethanolic solution of haloalkane with silver nitrite ($\ce{Ag-O-N=O}$), nitroalkane is formed because since the bond between $\ce{Ag-O}$ is covalent, the lone pair on nitrogen acts as an ...
Nilay Ghosh's user avatar
  • 25.6k
8 votes

Selective nitro reduction of poly nitro compounds

Source: Maity, Sunil K.; Pradhan, Narayan C.; Patwardhan, Anand V. "Reduction of p-nitrotoluene by aqueous ammonium sulfide: Anion exchange resin as a triphasic catalyst". Chemical Engineering Journal....
Nilay Ghosh's user avatar
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8 votes

Selective reduction of nitro group to amine, in benzene ring containing nitrile?

My answer is intended to support Waylander's suggestion elsewhere. I thought it'd be better to give OP some insight of this reduction mentioned (Ref.1). To my knowledge, after doing thorough ...
Mathew Mahindaratne's user avatar
8 votes

Can primary amine be produced using Grignard reagent?

Grignard reagents, in addition to being nucleophiles, are strong bases. Attempting to react a Grignard $\ce{RMgX}$ with nitrous acid is simply going to result in protonation of the Grignard to give $\...
Waylander's user avatar
  • 22.3k
7 votes

Is synthesis of nitrobenzene possible without nitric and sulfuric acids?

It's getting on for 3 decades since since I've done organic, so a proper organic chemist can probably give a more complete answer, but yes, there are other ways to do this. In the $\ce{HNO3}$/$\ce{...
Ian Bush's user avatar
  • 3,049
7 votes
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Are there any reducing agents for reduction of nitrobenzene to aniline other than Sn/HCl?

Hydrogenation of aromatic nitro groups (over, for example, $\ce{Pd/C}$) usually results in reduction to the corresponding aniline and is probably easier to carry out and work up as compared to $\ce{Sn/...
orthocresol's user avatar
7 votes
Accepted

Why is Aniline a poor substrate for Nitration reaction?

In the case of option c, the $\ce{-OCOCH_3}$ group will not be showing $\mathrm{-M}$ effect as the ring is directly attached to the oxygen atom. The group rather shows $\mathrm{+M}$ effect because of ...
Aniruddha's user avatar
  • 462
7 votes

What compound was drawn on this sidewalk?

The inner of the structure formula neither is a character, nor a number. It is a Thiele ring (suggested by Johannes Thiele 1865-1918 by 1899) to describe aromaticity, after Kekulé's approach already ...
Buttonwood's user avatar
  • 29.7k
6 votes

Selective reduction of nitro group to amine, in benzene ring containing nitrile?

$\ce{SnCl2.2H2O}$ in refluxing $\ce{EtOAc}$ as reported by Bellamy & Ou here will do this very cleanly. Work up into ice then add concentrated $\ce{NaOH}$ until you get phase separation. I have ...
Waylander's user avatar
  • 22.3k
6 votes

Most favorable position of attack of an electrophile on 4-trifluoromethyl-1,2-diphenylbenzene

In this question, we need to find the most electron-rich carbon out of positions $1,2,3,4,5,6$ in the compound given below: We proceed using the process of elimination. Note: Not sure how scientific ...
Safdar Faisal's user avatar
6 votes
Accepted

Can primary amine be produced using Grignard reagent?

Yes indeed. Primary amines can be made using Grignard reagent. The first reported instances of such reaction was found during the 1930s where they used mono/dihaloamines and reacted with Grignard ...
Nilay Ghosh's user avatar
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5 votes
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What is the function of nitrobenzene as a solvent in Friedel Crafts alkylation reaction?

The aluminium halide complexes with nitro compounds (e.g., nitrobenzene) are known to display catalytic properties in some organic reactions, including that in Friedel craft alkylations. Those ...
Mathew Mahindaratne's user avatar
5 votes

What is the function of nitrobenzene as a solvent in Friedel Crafts alkylation reaction?

Without any more information, it's just that, a solvent. Since it is a poor substrate for Friedel Crafts alkylations, it can be considered inert in these conditions. The choice of nitrobenzene would ...
ralk912's user avatar
  • 1,538
5 votes
Accepted

Is Nitroglycerine a Nitro Compound or an Ester?

The Oxford dictionary is correct. A nitro compound is defined by the $\ce{-NO2}$ functional group, but only if that group is attached to a carbon atom. Once an additional oxygen is added, the ...
Jan's user avatar
  • 68k
5 votes
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Major product in nitration

Read this first: Why methyl group is 2,4-directing? From that answer, we understand that methyl groups (or alkyl groups in general) are o/p directing because of hyperconjugation, and not inductive ...
Gaurang Tandon's user avatar
5 votes

Compatibility of Grignard reagents with aromatic nitro groups

Aromatic nitro groups are not compatible with Grignards as they react with the nitro group. An example of this being useful is the Bartoli synthesis of indoles from vinyl Grignards (Tet. Letts. 1989, ...
Waylander's user avatar
  • 22.3k
5 votes
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Preference for tin or iron in the reduction of nitrobenzene

The book's reasoning is correct. Fe/HCl gives $\ce{FeCl2}$ on reaction and it gets hydrolyzed by steam vapors to produces more hydrochloric acid and hydrogen to push the reaction forward thus making ...
Nilay Ghosh's user avatar
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5 votes
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Nitro-substitution

The reaction given in options (a) and (b) are called formation of nitrate esters. The following nitrate ester is called "ethyl nitrate", Firstly, $\ce{HNO3}$ and $\ce{H2SO4}$ reacts to form ...
Rahul Verma's user avatar
  • 3,071
5 votes
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Nitration vs Nitrolysis

Tert-butyl esters are routinely cleaved by anhydrous acid conditions by loss of the tBu+ cation. TFA in DCM is a common system for this. Neat formic acid, HBr/AcOH and PTSA in refluxing benzene or ...
Waylander's user avatar
  • 22.3k

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