Benzene to aniline

Nitrobenzenethe simplest aromatic nitro compoundhaving the molecular formula C 6 H 5 NO 2. It is used in the manufacture of anilinebenzidine, and other organic chemicals. Nitrobenzene is a colourless to pale yellow, oily, highly toxic liquid with the odour of bitter almonds. Nitrobenzene was first prepared in by the German chemist Eilhardt Mitscherlichwho treated benzene with fuming nitric acid. Commercially, both batch and continuous processes employing mixed nitric and sulfuric acids are used to make nitrobenzene.

Nitrobenzene undergoes nitration, halogenation, and sulfonation much more slowly than does benzene. It may be reduced to a variety of compoundsdepending on the reaction conditions. Most nitrobenzene produced is reduced to aniline; smaller amounts are converted to azobenzene, hydrazobenzene the intermediate for benzidineand phenylhydroxylamine.

Reduction of both the nitro group and the benzene ring affords cyclohexylamine. Nitrobenzene is used as a mild oxidizing agent in the syntheses of quinoline and fuchsin. Info Print Cite.

The method of purification of aniline

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Learn More in these related Britannica articles:. Applying an external electric field partially aligns the otherwise randomly oriented dipole moments and greatly enhances the influence of the field on the index of refraction. The length of the path of…. The former is reduced to aniline by treatment with hydrogen over a catalyst or by means of other reagents, such as iron or hydrogen sulfide Fe and H 2 S, respectively.

Aniline is made from chlorobenzene by treatment with ammonia at a…. Eilhardt MitscherlichGerman chemist who promulgated the theory of isomorphism, a relationship between crystalline structure and chemical composition.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

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benzene to aniline

The first reaction is called a catalytic reduction. Here is a picture of how it works with an olefin like ethylene. You can see that the first step involves adsorption of hydrogen onto the catalyst surface followed by dissociation of the hydrogen molecule into its catalytically active form. The same things happen with nitrobenzene.

Difference Between Aniline and Benzylamine

As the following diagram shows, the reduction passes through the nitroso and hydroxylamine intermediates. This diagram shows the electron transfers involved. Sign up to join this community.

Resonance Structures of Aniline

The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. Reaction mechanism for reduction of nitrobenzene to aniline in catalytic and acidic media Ask Question.

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benzene to aniline

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Preparing aniline from nitrobenzene | reduction of nitrobenzene

Responding to the Lavender Letter and commitments moving forward. Linked 0. Related 7. Hot Network Questions. Question feed. Chemistry Stack Exchange works best with JavaScript enabled.Aniline is an organic compound with the formula C 6 H 5 NH 2. Consisting of a phenyl group attached to an amino groupaniline is the simplest aromatic amine.

Its main use is in the manufacture of precursors to polyurethane and other industrial chemicals. Like most volatile amines, it has the odor of rotten fish. It ignites readily, burning with a smoky flame characteristic of aromatic compounds. Aniline is a slightly pyramidalized molecule, with hybridization of the nitrogen somewhere between sp 3 and sp 2. The amine is flatter than an aliphatic amine, owing to conjugation of the lone pair with the aryl substituent.

Thus, the experimental geometry reflects a balance between the stabilization of lone pairs in orbitals with higher s character and better stabilization via conjugation with the aryl ring for an orbital of pure p character. Industrial aniline production involves two steps. The reduction of nitrobenzene to aniline was first performed by Nikolay Zinin inusing inorganic sulfide as a reductant Zinin reaction.

Aniline can alternatively be prepared from ammonia and phenol derived from the cumene process. Many analogues of aniline are known where the phenyl group is further substituted. These include toluidinesxylidineschloroanilinesaminobenzoic acidsnitroanilinesand many others.

They often are prepared by nitration of the substituted aromatic compounds followed by reduction. For example, this approach is used to convert toluene into toluidines and chlorobenzene into 4-chloroaniline. The chemistry of aniline is rich because the compound has been cheaply available for many years.

Below are some classes of its reactions. The oxidation of aniline has been heavily investigated, and can result in reactions localized at nitrogen or more commonly results in the formation of new C-N bonds. In alkaline solution, azobenzene results, whereas arsenic acid produces the violet-coloring matter violaniline. Chromic acid converts it into quinonewhereas chloratesin the presence of certain metallic salts especially of vanadiumgive aniline black. Hydrochloric acid and potassium chlorate give chloranil.

Potassium permanganate in neutral solution oxidizes it to nitrobenzene ; in alkaline solution to azobenzeneammonia, and oxalic acid ; in acid solution to aniline black.

Hypochlorous acid gives 4-aminophenol and para-amino diphenylamine. These polymers exhibit rich redox and acid-base properties.

Like phenolsaniline derivatives are highly susceptible to electrophilic substitution reactions. Its high reactivity reflects that it is an enaminewhich enhances the electron-donating ability of the ring. If bromine water is added to aniline, the bromine water is decolourised and a white precipitate of 2,4,6-tribromoaniline is formed. To generate the mono-substituted product, a protection with acetyl chloride is required:.

The reaction to form 4-bromoaniline is to protect the amine with acetyl chloride, then hydrolyse back to reform aniline. The largest scale industrial reaction of aniline involves its alkylation with formaldehyde. An idealized equation is shown:. The resulting diamine is the precursor to 4,4'-MDI and related diisocyanates. Aniline is a weak base. Aromatic amines such as aniline are, in general, much weaker bases than aliphatic amines. Traditionally, the weak basicity of aniline is attributed to a combination of inductive effect from the more electronegative sp 2 carbon and resonance effects, as the lone pair on the nitrogen is partially delocalized into the pi system of the benzene ring.

Missing in such analysis is consideration of solvation. Aniline is, for example, more basic than ammonia in the gas phase, but ten thousand times less so in aqueous solution.Write chemical reaction of aniline with benzoyl chloride and write the name of the product obtained. Henry's law constant for CO 2 in water is 1. Calculate the quantity of CO 2 in mL of soda water when packed under 2. If the density of solution is 1.

The vapour pressure of pure liquids A and B are and mm Hg respectively, at K. Find out the composition of the liquid mixture if total vapour pressure is mm Hg. Also find the composition of the vapour phase.

benzene to aniline

H 2 S, a toxic gas with rotten egg like smell, is used for the qualitative analysis. Calculate k at K and E a. Explain how vacancies are introduced in an ionic solid when a cation of higher valence is added as an impurity in it. Write structures of different isomers corresponding to the molecular formula, C 3 H 9 N. Accountancy Chemistry Physics Biology Mathematics.

Question 3 How will you convert? Previous Question Next Question. Popular Questions of Class 12th chemistry Q:- Give simple chemical tests to distinguish between the following pairs of compounds. Q:- How the following conversions can be carried out? Q:- H 2 S, a toxic gas with rotten egg like smell, is used for the qualitative analysis. Q:- Predict which of the following will be coloured in aqueous solution? Give reasons for each. Q:- How do you explain the absence of aldehyde group in the pentaacetate of D-glucose?

Q:- Explain how vacancies are introduced in an ionic solid when a cation of higher valence is added as an impurity in it.

Q:- Why is sulphuric acid not used during the reaction of alcohols with KI? Q:- State Henry's law and mention some important applications?This page looks in outline at the preparation of phenylamine also known as aniline or aminobenzene starting from benzene.

The benzene is first converted to nitrobenzene which is in turn reduced to phenylamine. Benzene is nitrated by replacing one of the hydrogen atoms on the benzene ring by a nitro group, NO 2. The mixture is held at this temperature for about half an hour. Yellow oily nitrobenzene is formed. The temperature is kept relatively low to prevent more than one nitro group being substituted onto the ring. Nitrobenzene is reduced to phenylammonium ions using a mixture of tin and concentrated hydrochloric acid.

The mixture is heated under reflux in a boiling water bath for about half an hour. Under the acidic conditions, rather than getting phenylamine directly, you instead get phenylammonium ions formed. The lone pair on the nitrogen in the phenylamine picks up a hydrogen ion from the acid.

Combining them into full equations leads you to some really scary equations where it is difficult to see what is going on. The problem is made much worse because the tin ions formed go on to react with chloride ions from the hydrochloric acid to form complex ions such as [SnCl 6 ] If you aren't sure about electron-half-equations you could follow this link - but it really isn't important for UK A level purposes to worry too much about this in the present context.

You are unlikely to need much more than the conditions for the reaction. Use the BACK button on your browser to return to this page if you should decide to follow this link. The phenylamine is formed together with a complicated mixture of tin compounds from reactions between the sodium hydroxide solution and the complex tin ions formed during the first stage. The phenylamine is finally separated from this mixture.

The separation is long, tedious and potentially dangerous - involving steam distillation, solvent extraction and a final distillation. If you want details, refer to any good practical organic chemistry textbook.

If this is the first set of questions you have done, please read the introductory page before you start. Benzene to nitrobenzene Benzene is nitrated by replacing one of the hydrogen atoms on the benzene ring by a nitro group, NO 2. You could write this in a more condensed form as: The concentrated sulphuric acid is acting as a catalyst and so isn't written into the equations.Principle : Aniline undergoes nucleophilic substitution with bromine, even in cold.

The bromine atoms enter at the two ortho positions and the para position with the formation of 2,4,6-tribromoaniline. Here presence of bromine atoms in tribroboaniline, reduces the basic properties of the amino group, and salts even with strong acids are almost completely hydrolysed in presence of water.

Aim : To prepare 2, 4, 6-tribromoaniline from aniline. Reaction :. Mechanism :. Use : It is used in organic synthesis of pharmaceuticals, agrochemicals and fire-extingushing agents.

Bromine — 6. Dilute hydrochloric acid. Rectified sprit. Filtration set etc. Method: 1. The apparatus is assembled as shown in fig. A ml. Buchner flask A is fitted with a cork through which passes a glass delivery tube B reaching nearly to the bottom of A. B is then connected by a short piece of rubber tubing to the side-arm of a ml. A narrow glass tube D is then fitted as shown so that it reaches within cm.

The position of the tube D is adjusted until it touches the surface of the bromine layer. A is connected to a suction water-pump, so that a steady stream of bromine vapour carries from C into A, where the greyish-white tribromoaniline soon begins to separate. The contents of A is shaken occasionally for even distribution of tribromoaniline. When the water in C becomes almost colourless about 40 minutesdue to evaporation of bromine, the current of air is stopped, and tribromoaniline is filtered at pump, washed well with water and drained.

The product is recrystallised from rectified spirit, using animal charcoal. If reported Practical yield is 8. A solution is prepared by adding 8. Another second solution is prepared adding 5 ml of aniline in 20 ml of glacial acetic acid in a conical flask.

The first solution is added drop wise to the second solution from a dropping funnel. During addition, the flask is shaken time to time and cooled in ice. A yellow coloured mass is obtained. It is poured into excess of water. The separated product is filtered, washed with water and recrystallised from rectified spirit.

The yield is about 10 g Esters are hydrolysed either by an acid or a base. Alkaline hydrolysis of ester is irreversible which is alsoThe key difference between aniline and benzylamine is that the amine group of aniline is attached to the benzene ring directly whereas the amine group of benzylamine is attached to the benzene ring indirectly, through a —CH 2 — group.

Aniline and benzylamine are aromatic organic compounds. Both these compounds contain benzene rings and amine groups, but the amine group attach the benzene in different ways; either directly or indirectly. Therefore, the two compounds have different chemical and physical properties.

benzene to aniline

Overview and Key Difference 2. What is Benzylamine 4. Aniline is an aromatic organic compound having the chemical formula C 6 H 5 NH 2. It has a phenyl group a benzene ring with an attached amine group -NH2. It is the simplest aromatic amine. Moreover, this compound is slightly pyramidalized and is flatter than an aliphatic amine. Its molar mass is It has the odour of rotten fish.

Industrially, we can produce this compound via two steps. It gives nitrobenzene. Then, we can hydrogenate nitrobenzene into aniline in the presence of a metal catalyst. The reaction is as follows. Furthermore, this compound is mainly used in the manufacture of polyurethane precursors. Apart from that, we can use this compound in the production of dyes, drugs, explosive materials, plastics, photographic and rubbery chemicals, etc.

It has an amine group attached to a phenyl group via a —CH2- group.

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Besides, this compound occurs as a colourless liquid, and it has an ammonia-like odour. The molar mass of Benzylamine is We can produce this compound via the reaction of benzyl chloride with ammonia. Also, we can produce it by benzonitrile reduction. Moreover, this compound is a common precursor for organic synthesis and the production of many pharmaceuticals.

The key difference between aniline and benzylamine is that in aniline the amine group attaches with the benzene ring directly whereas in benzylamine the amine group attaches the benzene ring indirectly, through a —CH2- group. Moreover, we can produce aniline via nitration of benzene followed by hydrogenation nitrobenzene into aniline whereas we can produce benzylamine via reaction of benzyl chloride with ammonia.

Besides, a further difference between aniline and benzylamine is their odour. Aniline has the odour of rotten fish while the odour of benzylamine is similar to the odour of ammonia. In summary, the key difference between aniline and benzylamine is that in aniline, the amine group attaches with the benzene ring directly whereas, in benzylamine, the amine group attaches the benzene ring indirectly, through a —CH 2 — group.

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