Green Chemistry

Green Chemistry

Principles of Green Chemistry

  • Waste Prevention: Prioritises processes which minimise the quantity of waste generated in drug synthesis.
  • Safer Design: Aims to develop drugs where ingredients and by-products pose minimal risk to human health and the environment.
  • Less Hazardous Chemistry: Utilises less hazardous and more sustainable chemical reactions, reducing potential harm to patients and healthcare workers.
  • Energy Efficiency: Advocates for methods that require less energy (like room temperature and pressure conditions), greater atom economy, and have low E Factors (gram waste per gram product).

Atom Economy and E Factors

  • Atom Economy: Measure of the amount of starting materials that become useful products. High atom economy is desirable in green chemistry.
  • E Factors: The ratio of wastage to product output. Lower E Factors are desired in green chemistry.

Example of a Green Synthesis: Aspirin

  • The synthesis of salicylic acid from willow bark is an example of a green chemistry process.
  • It is a highly atom economical process with little to no waste.
  • It takes place at room temperature and pressure, demonstrating energy efficiency.
  • Reducing agents used, like sodium formate, are less hazardous, aligning with the principle of less hazardous chemistry.

Greener Alternatives

  • Use of Renewable Feedstocks: Raw materials should be renewable whenever technically and economically viable.
  • Green Catalysis: Catalysts can make reactions more selective, reducing the amount of waste products.
  • Green Solvents: Less hazardous and harmful solvents should be used where possible.

Monitoring Green Processes

  • Real-Time Analysis for Pollution Prevention: By monitoring reactions in real-time, adjustments can be made to prevent or minimise environmental impact before it happens.
  • Green Analytical Techniques: Such as microscale titrations and spectrophotometry, which use minimal amounts of reagents and solvents, reducing waste and exposure to potentially harmful substances.

Role in Medicine

  • To ensure a more sustainable pharmaceutical industry, green chemistry principles need to be incorporated into the medicinal chemistry practice.
  • Reduces environmental footprint of healthcare sector by minimising waste and hazardous chemicals.
  • Better for patient and healthcare worker safety by reducing exposure to potentially harmful substances.
  • Cost-effective by improving efficiency and reducing waste management requirements.