Named Reactions in Organic Chemistry

Named reactions are organic reactions that have become well-known and are named after the scientists who discovered or developed them. These reactions are essential tools in organic chemistry and are widely used in synthetic pathways, lab work, and industrial processes.

Why important? Knowing named reactions helps you recognize patterns, predict products, and build complex molecules efficiently.

Important Named Reactions in Organic Chemistry

1. Aldol Condensation Reaction

Type: Carbon-carbon bond-forming reaction

Reactants: Aldehyde or ketone with α-hydrogen

Product: β-hydroxy aldehyde or β-hydroxy ketone (which may further dehydrate)

Application: Used in building complex carbon frameworks

2. Cannizzaro Reaction

Type: Redox reaction

Reactants: Aldehydes without α-hydrogens + base

Products: One molecule forms alcohol, the other forms carboxylic acid

3. Sandmeyer Reaction

Type: Substitution reaction

Reactants: Aromatic diazonium salt + CuX (X = Cl, Br, CN)

Product: Aryl halides or nitriles

Application: Introduction of halogen or CN group into aromatic rings

4. Friedel–Crafts Alkylation/Acylation Reaction

Type: Electrophilic aromatic substitution

Reactants: Benzene + alkyl/acyl halide + Lewis acid (AlCl₃)

Products: Alkylbenzene or Acylbenzene

Use: Widely used in pharmaceuticals and fragrances

5. Hell–Volhard–Zelinsky Reaction

Type: Halogenation of carboxylic acids

Reactants: Carboxylic acids + halogen + red phosphorus

Product: α-halo acids

6. Reimer–Tiemann Reaction

Type: Electrophilic substitution

Reactants: Phenol + chloroform + base

Product: Ortho-hydroxybenzaldehyde (salicylaldehyde)

Type: Nucleophilic substitution

Reactants: Potassium phthalimide + alkyl halide

Product: Primary amine

8. Kolbe Reaction

Type: Electrophilic substitution

Reactants: Sodium phenoxide + CO₂

Product: Salicylic acid

Applications of Named Reactions in Organic Chemistry

7. Gabriel Phthalimide Synthesis

• Drug synthesis (e.g., aspirin via Kolbe reaction)
• Industrial fragrance and dye production
• Widely tested in competitive exams (IIT-JEE, NEET, CSIR-NET)

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Quiz: Named Reactions in Organic Chemistry

1. Which reaction converts aldehydes without α-hydrogens into alcohol and acid?
2. Which reaction introduces -Cl or -Br into an aromatic ring using CuCl/CuBr?
3. What are the products of Aldol condensation?
4. Which named reaction is used to prepare primary amines?
5. What reagent is used in the Friedel–Crafts reaction?

Answers:

1. Cannizzaro Reaction
2. Sandmeyer Reaction
3. β-hydroxy aldehyde or ketone (may dehydrate to α,β-unsaturated carbonyl)
4. Gabriel Phthalimide Synthesis
5. AlCl₃ (aluminium chloride)