Complete the following reactions by writing the structure of the main products:
Complete the following reactions by writing the structure of the main products:
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Solution and Explanation
Reaction (I)
Reactants: Cyclohexanone + Semicarbazide (H2NCONH–NH2)
Reaction Type: Formation of semicarbazone (nucleophilic addition–elimination reaction with carbonyl compound)
Product: Cyclohexanone semicarbazone
Structure of Product:
Cyclohexane ring – C=N–NH–CO–NH2
This is formed by condensation of the carbonyl group (=O) with semicarbazide, replacing =O with =N–NH–CO–NH2.
Reaction (II)
Reactants: Dimethyl cadmium [(CH3)2Cd] + 2 molecules of acetyl chloride (CH3COCl)
Reaction Type: Ketone synthesis via organocadmium reagent
Product: 2 molecules of butan-2-one (CH3COCH2CH3)
Balanced Reaction:
(CH3)2Cd + 2 CH3COCl → 2 CH3COCH3 (acetone) + CdCl2
Reaction (III)
Reactants: Benzoyl chloride (C6H5COCl) + H2 in presence of Pd–BaSO4
Reaction Type: Rosenmund reduction
Product: Benzaldehyde (C6H5CHO)
Mechanism: The acid chloride is selectively reduced to aldehyde using hydrogen and poisoned palladium catalyst (Pd–BaSO4).
Summary of Products:
- (I): Cyclohexanone semicarbazone
- (II): Acetone (2 molecules)
- (III): Benzaldehyde
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Write IUPAC names of the following compounds and classify them into primary, secondary and tertiary amines.
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Give one chemical test to distinguish between the following pairs of compounds.
(i) Methylamine and dimethylamine
(ii) Secondary and tertiary amines
(iii) Ethylamine and aniline
(iv) Aniline and benzylamine
(v) Aniline and N-methylanilineAccount 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.
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