Organic Compounds Containing Nitrogen MCQ Questions & Answers in Organic Chemistry | Chemistry

\[C{{H}_{3}}CN+2H\to \underset{X}{\mathop{C{{H}_{3}}CH}}\,=NH\xrightarrow{{{H}_{2}}O,\text{boil}}\underset{Y}{\mathop{C{{H}_{3}}CHO}}\,\]
Note that cyanides are reduced only by $$2H$$  atoms, so reduction stops at aldimine stage which on hydrolysis with water gives aldehyde; it is an example of Stephen’s reaction.

$$N{H_3} + \mathop {{C_2}{H_5}I}\limits_{\left( {{\text{Excess}}} \right)} \to \mathop {\left[ {{{\left( {{C_2}{H_5}} \right)}_4}{N^ + }} \right]{I^ - }}\limits_{{\text{Quaternary salt}}} $$

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Nitro compounds having $$\alpha $$ - hydrogen show tautomerism

As the number of alkyl groups increases, the electron density on nitrogen atom also increases, so the basic character increases but $${3^ \circ }$$ amines are less basic than $${2^ \circ }$$ amines due to steric hindrance of $${3^ \circ }$$ amines, so the correct order of basicity is
$${\text{Ammonia}} < {1^ \circ } < {3^ \circ } < {2^ \circ }$$
$$N{H_3} < {C_2}{H_5}N{H_2} < {\left( {{C_2}{H_5}} \right)_3}N$$       $$ < {\left( {{C_2}{H_5}} \right)_2}NH$$

Two moles of $$N{H_2}$$   ions will abstract two moles of most acidic hydrogen out of the four moles of hydrogen present per mole of the acidic compound. The acidic strength is in the order :
$$ - COOH > - OH$$    $${\text{(phenolic having }}N{O_2}{\text{ group) }}$$    $${\text{ > }} - OH{\text{ (phenolic) > alkynic }}H{\text{.}}$$

compound is most basic due to presence of localized lone pair of electron on nitrogen atom while other compounds have delocalized lone pair of electron.

Mechanism :

The complete reaction is

The above reaction is a coupling reaction of aniline with diazonium salt to give azo benzene compound. This coupling reaction takes place at the $$para$$  - position to $$ - N{H_2}$$  group of benzene. This reaction act as electrophilic substitution reaction of aniline.