Aryl Diazonium Salts A Versatile Tool in Organic Synthesis.pptx

Aryl Diazonium Salts A Versatile Tool in Organic Synthesis.pptx

1. Aryl Diazonium Salts: A Versatile Tool in Organic Synthesis by Deepak Musmade Assistant Professor Department of Pharmaceutical Chemistry Sanjivani College of Pharmaceutical Education and Research, Kopargaon

2. Synthetic Reactions of Aryl Diazonium Salts 1 Diazotization The formation of aryl diazonium salts involves the reaction of primary aromatic amines with nitrous acid. 2 Nucleophilic Aromatic Substitution Aryl diazonium salts can undergo nucleophilic aromatic substitution reactions, leading to the formation of a variety of substituted aromatic compounds. 3 Reduction Aryl diazonium salts can be reduced to form aromatic hydrocarbons by using various reducing agents. 4 Halogenation Aryl diazonium salts can be converted to aryl halides by reacting them with cuprous halides in a Sandmeyer reaction.

3. Azo Coupling Reactions Mechanism The azo coupling reaction involves the electrophilic attack of an aryl diazonium salt on an electron-rich aromatic compound. Products Azo coupling reactions produce azo compounds, which are highly colored and are widely used as dyes. Applications Azo dyes are used in various industries, including textiles, food, and cosmetics.

4. Sandmeyer Reactions Diazonium Salt An aryl diazonium salt is treated with a copper(I) halide. Aryl Halide The reaction yields an aryl halide, where the diazonium group is replaced by a halogen. Applications The Sandmeyer reaction is an essential tool for the synthesis of various aryl halides, which are valuable intermediates in organic synthesis.

5. Gomberg-Bachmann Reactions Aryl Radicals The Gomberg-Bachmann reaction generates aryl radicals from aryl diazonium salts. Aromatic Coupling The aryl radicals couple with other aromatic compounds to form biaryl compounds. Applications This reaction is useful for synthesizing various biaryl compounds, which are important building blocks in organic synthesis.

6. Gattermann-Koch Reactions Reactants Aryl Diazonium Salt Carbon Monoxide Hydrochloric Acid Catalyst Copper(I) Chloride Product Aromatic Aldehyde Applications Synthesis of Aromatic Aldehydes

7. Pschorr Cyclization 1 Diazonium Salt An aryl diazonium salt containing an ortho-substituted aromatic ring is treated with a reducing agent. 2 Aryl Radical The diazonium group is reduced to form an aryl radical. 3 Cyclization The aryl radical undergoes intramolecular cyclization to form a new aromatic ring.

8. Balz-Schiemann Reaction Aryl Fluoride The Balz-Schiemann reaction converts aryl diazonium salts to aryl fluorides. Tetrafluoroborate Salt The diazonium salt is first converted to its tetrafluoroborate salt.

9. Applications of Aryl Diazonium Salts Dyes Azo dyes are extensively used in the textile, food, and cosmetic industries. Pharmaceuticals Aryl diazonium salts are utilized in the synthesis of various pharmaceutical compounds. Polymers Aryl diazonium salts are employed in the production of polymers with specific properties. Electronics Aryl diazonium salts are used in the fabrication of electronic devices.

10. Conclusion and Future Directions Aryl diazonium salts are valuable reagents in organic synthesis, offering diverse possibilities for creating new and useful compounds. Future research will focus on exploring their applications in advanced materials, nanotechnology, and sustainable chemistry.