Chemical Reactions

It is expected that the basic nature of amines should be in order tertiary > secondary > primary but the observed order in the case of lower members is found to be as secondary > Primary > tetriary. This anomalous behaviour of tetriary amines is due to steric factors i.e crowding of alkyl groups cover nitrogen atom from all sides thus makes the approach and bonding by a proton relatively difficult which results the maximum steric strain in tetiary amines. The electrons are there but the path is blocked, resulting the reduction in basicity.
Thus the correct order is

Benzaldehyde reacts with ammonia to form hydrobenzamide.

Carbylamine test is given by aliphatic primary amine.
Aliphatic (or aromatic) Bad smelling isocyanide.

In presence of or , phenol reacts with alkyl halide and gives phenolic ether .

Vapours of and , with red hot (thoria) give anisole (phenolic ether).

In presence of dil , acetamide is hydrolysed by boiling, the product obtained is acetic acid

When ethyl alcohol is heated with conc at the product obtained is ethylene


but at lower temperature ether is formed

Only aromatic amine (primary aromatic amine) form diazonium salts at low temperature . A reaction in which group is converted into diazo group is called diazotisation. Diazotised salts are stable in cold aqueous solution.




aromatic primary amines, so undergo diazotisation but (aliphaticamine) will not undergo diazotisation.

An alkyl cyanide is dissolved in ether or better in ethyl formate or ethyl acetate, and reduced with and , and then steam distilled. This whole process is called Stephen reaction. In this process alkyl cyanide is reduced to aldehyde.

There is no analogous method for the preparation

Gattermann aldehyde synthesis reaction is

Aldehydes which have no -H atom give Cannizzaro?s reaction, does not contain -H atom, hence it will give Cannizzaro reaction.

p-toluidine contains amino group attached directly to benzene ring, thus undergo diazotisation reaction and gives red dye. In benzyl amine, the amino group is not directly attached to benzene ring. Hence, it will not undergo diazotisation reaction.
Thus, these two can be distinguished by dye test.

oxidises compounds containing active methylene (i.e., next to the carbonyl group) to another CO group.

Compounds having either - group or group, give iodoform when warmed when and .
Thus, ,

give iodoform when warmed with and Remember, xidises to , thus it gives positive iodoform test.)

Since alkyl group has -effect and aryl group has -effect, thus greater the number of alkyl and aryl groups attached to the carbonyl group, its reactivity towards nucleophilic addition reaction. Secondly, as the steric crowding on carbonyl group increases, the reactivity decreases accordingly.
Correct reactivity order for reaction with is

Dehydration of alcohols involve formation of carbocation intermediate. More the stability of carbocation, higher is the ease of dehydration. The order of stability of carbocation, given by the given compounds is

Thus, compound given in option (c) readily undergoes dehydration.

Keto group is more reactive for addition of Grignard reagent.

On the other hand Wurtz reaction of gives. n-butane and hydrolysis of n-butyl magnesium bromide gives n-butane but reduction of propanol with HI/P gives propane.

Although in both cases products are and ; the two reactions follow different mechanism.


Remember that during reaction, is formed because it is more stable than .

Benzaldyde and formaldehyde, both do not have a - hydrogen atom, so both will undergo Cannizzaro reaction; here formaldehyde will always be oxidised to formate while the other aldehyde ( or any other aldehyde not having , viz- ) will always be reduced to corresponding alcohol (crossed Cannizzaro reaction)

Reaction involved is given as :

and react with acetophenone to give yellow ppt. of but benzophenone does not and hence can be used to distinguish between them.

A ring structure