GREEN CHEMISTRY
Introduction to Green Chemistry
What is Green Chemistry? Need for Green Chemistry. Goals of Green Chemistry.
Limitations/ Obstacles in the pursuit of the goals of Green Chemistry.
(4 Lectures)
Principles of Green Chemistry and Designing a Chemical synthesis
Twelve principles of Green Chemistry with their explanations and examples; Designing a Green
Synthesis using these principles; Prevention of Waste/ byproducts; maximum incorporation of the
materials used in the process into the final products (Atom Economy); prevention/ minimization of
hazardous/ toxic products; designing safer chemicals – different basic approaches to do so; selection
of appropriate auxiliary substances (solvents, separation agents), green solvents, solventless processes,
immobilized solvents and ionic liquids; energy requirements for reactions - use of microwaves,
ultrasonic energy; selection of starting materials; avoidance of unnecessary derivatization –
careful use of blocking/protecting groups; use of catalytic reagents (wherever possible) in preference
to stoichiometric reagents; designing of biodegradable products; prevention of chemical accidents;
strengthening/ development of analytical techniques to prevent and minimize the generation of
hazardous substances in chemical processes.
(24 Lectures)
Examples of Green Synthesis/ Reactions
1. Green Synthesis of the following compounds: adipic acid, catechol, BHT, methyl methacrylate,
urethane, aromatic amines (4-aminodiphenylamine), benzyl bromide, acetaldehyde, disodium iminodiacetate (alternative to Strecker synthesis), citral, ibuprofen, paracetamol, furfural.
2. Microwave assisted reactions in water: Hofmann Elimination, Hydrolysis (of benzyl chloride,
benzamide, n-phenyl benzamide, methylbenzoate to benzole acid), Oxidation (of toluene, alcohols).
Microwave assisted reactions in organic solvents: Esterification, Fries rearrangement, Orthoester
Claisen Rearrangement, Diels-Alder Reaction, Decarboxylation.
3.Microwave assisted solid state reactions: Deacetylation, Deprotection. Saponification of esters,
Alkylation of reactive methylene compounds, reductions, synthesis of nitriles from aldehydes;
anhydrides from dicarboxylic acid; pyrimidine and pyridine derivatives; 1,2-dihydrotriazine
derivatives; benzimidazoles.
4. Ultrasound assisted reactions:
Esterification, saponification, substitution reactions, Alkylations,
oxidation, reduction, coupling reaction, Cannizaro reaction, Strecker synthesis, Reformatsky reaction.