Suggest a route by which the following conversion can be accomplished.
Describe a method for the identification of primary, secondary and tertiary amines. Also write chemical equations of the reactions involved.
Under which of the following reaction conditions, aniline gives p-nitro derivative as the major product?
(a) Acetyl chloride/pyridine followed by reaction with cone. H2SO4 + cone.
(b) Acetic anhydride/pyridine followed by cone. H2SO4 + cone. HNO3
(c) Dil. HCl followed by reaction with cone. H2SO4 + cone. HNO3
(d) Reaction with cone. HNO3 + cone. H2S04
Why is benzene diazonium chloride not stored and is used immediately after its preparation?
Which of the following reactions belong to electrophilic aromatic substitution?
(a) Bromination of acetanilide
(b) Coupling reaction of aryldiazonium salts
(c) Diazotisation of aniline
(d) Acylation of aniline
Complete the following acid-base reactions and name the products:
(i) CH3CH2CH2NH2+HCl ——–>
(ii) (C2H5)3 N+HCl ——–>
How wjll you convert:
(i) Ethanoic acid into methanamine (ii) Hexanenitrile into 1-aminopentane
(iii) Methanol to ethanoic acid. (iv) Ethanamine into methanamine
(v) Ethanoic acid into propanoic acid (vi) Methanamine into ethanamine
(vii) Nitromethane into dimethylamine (viii) Propanoic acid into ethanoic acid?
Assertion (A): N, N-diethylbenzene sulphonamide is insoluble in alkalf. Reason (R): Sulphonyl group attached to nitrogen atom is strong electron withdrawing group.
Account for the following
(i)pKb of aniline is more than that of methylamine
(ii) Ethylamine is soluble in water whereas aniline is not.
(iii) Methylamine in water reacts with ferric chloride to precipitate hydrated ferric oxide.
(iv)Although amino group is o and p – directing in aromatic electrophilic substitution reactions, aniline on nitration gives a substantial amount of m-nitroaniline.
(v)Aniline does not undergo Friedel-Crafts reaction.
(vi)Diazonium salts of aromatic amines are more stable than those of aliphatic amines.
(vii)Gabriel phthalimide synthesis is preferred for synthesising primary amines.
Reduction of nitrobenzene by which of the following reagents give aniline?
(a) Sn/HCl (b) Fe/HCl (c) H2-Pd (d) Sn/NH4OH
Predict the product of reaction of aniline with bromine in non-polar solvent such as CS2.
Give plausible explanation for each of the following:
(i) Why are amines less acidic than alcohols of comparable molecular masses?
(ii) Why do primary amines have higher boiling point than tertiary amines?
(iii) Why are aliphatic amines stronger bases than aromatic amines?
The best reagent for converting 2-phenylpro-panamide into-2-phenyl- propanamine is .
(a) excess H2
(b) Br2 in aqueous NaOH
(c) iodine in the presence of red phosphorus
(d) LiAlH4 in ether
Amongst the given set of reactants, the most appropriate for preparing 2 ° amine is .
(a) 2 ° R – Br + NH3
(b) 2 ° R – Br + NaCN followed by H2/Pt
(c) 10 R – NH2 + RCHO followed by H2/Pt
(d) 1 ° R – Br + (2 mol) + potassium phthalimide followed by H3O+/heat
Which of the following species are involved in the carbylamine test?
(a) R-NC (b) CHCl3 (c) COCl2 (d) NaN02 + HCl
The reagents that can be used to convert benzene diazonium chloride to benzene are
(a) SnCl2/HCl (b) CH3CH2OH
(c) H3PO2 (d) LiAlH4
A solution contains 1 g mol each of p-toluene diazonium chloride and p-nitrophenyl diazonium chloride. To this 1 g mol of alkaline solution of phenol is added. Predict the major product. Explain your answer.
Which of the following is a 3 ° amine?
(a) 1 -Methylcyclohexylamine (c) tert-Butylamine
A primary amine, RNH2 can be reacted with CH3-X to get secondary amine, R NHCH3 but the only disadvantage is that 3 ° amine and quaternary ammonium salts are also obtained as side products. Can you suggest a method where RNH2 forms only 2 ° amine?
Assertion (A): Only a small amount of HCl is required in the reduction of nitro compounds with iron scrap and HCl in the presence of steam.
Reason (R): FeCl2 formed gets hydrolysed to release HCl during the reaction.
The best reagent for converting-2-phenylpro-panamide into 1-phenylethana- mine is .
(a) excess H2/Pt (b) NaOH /Br2
(c) NaBH4/methanol (d) LiAlH4/ether
A compound Z with molecular formula C3H9N reacts with C6H5SO2Cl to give a solid, insoluble in alkali, identify Z.
Assertion (A): Hofmann's bromamide reaction is given by primary amines. Reason (R): Primary amines are more basic than secondary amines.
Assertion (A): N-Ethylbenzene sulphonamide is soluble in alkali.
Reason (R): Hydrogen attached to nitrogen in sulphonamide is strongly acidic.
Arrange the following in increasing order of their basic strength: ‘
(i) C2H5NH2,C6H5NH2,NH3,C6H5CH2NH2 and(C2H5)2 NH
(ii) C2H5NH2,(C2H5)2NH,(C2H5)3N,C6H5NH2
(iii) CH3NH2, (CH3)2NH, (CH3)3N, C6H5NH2, C6H5CH2NH2
An aromatic compound 'A'on treatment with aqueous ammonia and heating forms compound 'B' which on heating with Br2 and KOH forms a compound 'C' of molecular formula C6H7N. Write the structures and IUPAC names of compounds A,B and C.
Give plausible explanation for each of the following:
(i) Why are amines less acidic than alcohols of comparable molecular masses?
(ii) Why do primary amines have higher boiling point than tertiary amines?
(iii) Why are aliphatic amines stronger bases than aromatic amines?
Write following conversions:
(i) nitrobenzene –> acetanilide
(ii) acetanilide –> p-nitroaniline
Assertion (A): Acetanilide is less basic than aniline.
Reason (R): Acetylation of aniline results in decrease of electron density on nitrogen.
