Named Reactions in Organic Chemistry
Class 12 – NCERT Syllabus

Haloalkanes and Haloarenes

• Wurtz reaction – Coupling of alkyl halides with sodium in dry ether to form higher alkanes.
• Fittig reaction – Coupling of aryl halides with sodium in dry ether to form diaryls (e.g. biphenyl).
• Wurtz–Fittig reaction – Coupling of alkyl and aryl halides with sodium in dry ether to form alkyl aryls.
• Grignard reagent formation – Preparation of RMgX by reaction of alkyl/aryl halides with Mg in dry ether; used widely for synthesis.
• Friedel–Crafts alkylation/acylation – Electrophilic substitution on aromatic rings using alkyl or acyl halides in presence of anhydrous AlCl₃.

Alcohols, Phenols and Ethers

• Kolbe reaction – Electrophilic substitution on sodium phenoxide with CO₂ followed by acidification to give salicylic acid (o-hydroxybenzoic acid).
• Reimer–Tiemann reaction – Formylation of phenol with chloroform and NaOH to give salicylaldehyde (o-hydroxybenzaldehyde).
• Williamson ether synthesis – Preparation of ethers by reaction of sodium alkoxide/phenoxide with primary alkyl halides.
• Cumene process – Industrial preparation of phenol (and acetone) from cumene (isopropylbenzene).

Aldehydes, Ketones and Carboxylic Acids

• Rosenmund reduction – Reduction of acid chlorides (acyl chlorides) to aldehydes using H₂ over Pd/BaSO₄.
• Stephen reaction – Reduction of nitriles to imines (with SnCl₂/HCl) followed by hydrolysis to give aldehydes.
• Etard reaction – Oxidation of the −CH₃ group of toluene to −CHO using chromyl chloride (CrO₂Cl₂).
• Gattermann–Koch reaction – Formylation of benzene/arenes with CO + HCl in presence of AlCl₃/CuCl to give benzaldehydes.
• Friedel–Crafts acylation – Acylation of benzene/arenes using acyl chlorides or anhydrides with AlCl₃ to give aromatic ketones.
• Clemmensen reduction – Reduction of carbonyl group (>C=O) of aldehydes/ketones to −CH₂ using Zn–Hg amalgam and conc. HCl.
• Wolff–Kishner reduction – Reduction of carbonyl group to −CH₂ via hydrazone formation followed by heating with KOH/NaOH in high-boiling solvent.
• Aldol reaction / Aldol condensation – Base-catalysed addition of carbonyl compounds having α-H to give β-hydroxy aldehydes/ketones, followed by dehydration to α,β-unsaturated carbonyls.
• Cross aldol condensation – Aldol condensation between two different aldehydes and/or ketones.
• Cannizzaro reaction – Disproportionation of aldehydes without α-H in presence of concentrated alkali to give alcohol and carboxylate.
• Haloform (iodoform) reaction – Oxidation of methyl ketones (or related alcohols) with halogen + base to give haloform (e.g. CHI₃) and carboxylate with one less C.
• Hell–Volhard–Zelinsky (HVZ) reaction – α-Halogenation of carboxylic acids (having α-H) with Cl₂/Br₂ in presence of red phosphorus.
• Decarboxylation – Removal of CO₂ from sodium salts of acids with soda-lime (NaOH + CaO) to give hydrocarbons.

Important Named Tests (in this chapter)

• Tollens’ test – Oxidation of aldehydes with ammoniacal AgNO₃ solution giving a silver mirror.
• Fehling’s test – Oxidation of aliphatic aldehydes with Fehling’s solution giving a reddish-brown Cu₂O precipitate.
• Haloform (iodoform) test – Detection of CH₃CO– or CH₃CH(OH)– group by formation of yellow iodoform (CH I₃).
• Kolbe electrolysis (mentioned under carboxylic acids) – Electrolytic decarboxylation of carboxylate salts giving hydrocarbons with double carbon atoms.

Amines

• Diazotisation – Conversion of primary aromatic amines to diazonium salts with NaNO₂/HCl at 273–278 K.
• Sandmeyer reaction – Replacement of the diazonium group (−N₂⁺) by Cl, Br or CN in presence of Cu(I) salts.
• Gattermann reaction – Replacement of diazonium group by Cl or Br using corresponding HX in presence of Cu powder.
• Coupling reaction – Reaction of diazonium salts with phenols or aromatic amines to form azo compounds (azo dyes).
• Carbylamine reaction (isocyanide test) – Primary amines with chloroform and alcoholic KOH give foul-smelling isocyanides.
• Hinsberg test – Distinction of primary, secondary and tertiary amines using benzenesulphonyl chloride (Hinsberg reagent).
• Gabriel phthalimide synthesis – Preparation of primary amines from phthalimide via N-alkyl/aryl phthalimide followed by hydrolysis.
• Hoffmann bromamide degradation (Hoffmann rearrangement) – Conversion of amides to primary amines with one carbon less using Br₂/KOH.

Other Organic Chapters (Biomolecules, Polymers, Everyday Life)

• These chapters mainly involve mechanisms and functional groups rather than classic named organic reactions; no major additional “named reactions” beyond those above are emphasised in NCERT Class 12.