Amines MCQs for NEET — Chemistry Questions with Answers

Deamination of n-Bu-NH2 using NaNO2/HCl gives a mixture of 1-butene, cis-2-butene, and trans-2-butene. The formation of isobutene is not possible as it requires a rearrangement which does not occur under these conditions.

Deamination (or diazotization) of n-Bu-NH2 with NaNO2/HCl gives a mixture of three isomeric butenes: 1-butene, cis-2-butene, and trans-2-butene. Therefore, the answer is 3 isomeric butenes.

(c) CH₃CN $\stackrel{\mathrm{Na}/{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}}{\to }$ CH₃CH₂NH₂  $\stackrel{{\mathrm{HNO}}_2}{\to }$CH₃CH₂OH$\stackrel{\left[\mathrm{O}\right]}{\to }$ CH₃CHO $\stackrel{\mathrm{Tollens} \mathrm{reagent}}{\to }$CH₃COOH

(d) CH₃CN$\stackrel{{\mathrm{H}}_2\mathrm{O}}{\to }$CH₃COOH$\stackrel{{\mathrm{NH}}_3}{\to }$CH₃COONH₄$\stackrel{∆}{\to }$CH₃CONH₂+H₂O

(c) ${\mathrm{C}}_2{\mathrm{H}}_5{\mathrm{NH}}_2 1+ \mathrm{Na} \stackrel{ }{\to }{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{NHNa} + \frac{1}{2}{\mathrm{H}}_2$

 ${\mathrm{C}}_2{\mathrm{H}}_5{\mathrm{NH}}_2\stackrel{\left[\mathrm{O}\right]}{\to }{\mathrm{CH}}_3\mathrm{CH}=\mathrm{NH}\stackrel{\mathrm{KOH}}{\to }{\mathrm{CH}}_3\mathrm{CHO} + {\mathrm{NH}}_3$

(a)

Amines serve as nucleophiles in attacking the sulfonyl chloride electrophile, displacing chloride. The sulfonamides resulting from primary and secondary amines are poorly soluble and precipitate as solids from solution:

PhSO₂Cl + 2 RR'NH → PhSO₂NRR' + [RR'NH₂⁺]Cl⁻

For primary amines (R' = H), the initially formed sulfonamide is deprotonated by base to give water-soluble sulfonamide salt (Na[PhSO₂NR]):

PhSO₂N(H)R + NaOH → Na⁺[PhSO₂NR⁻] + H₂O

Tertiary amines promote hydrolysis of the sulfonyl chloride functional group, which affords water-soluble sulfonate salts.

PhSO₂Cl + R₃N + H₂O → R₃NH⁺[PhSO₃⁻

(a) $R{\mathrm{NH}}_2+{\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{SO}}_2\mathrm{Cl} \stackrel{ }{\to }{\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{SO}}_2\mathrm{NH}R$

                (Sulphonamide

                soluble in alkali)