Operationally simple, scalable synthesis of aryloxy propanolamines using glycerol as a green promoting media: Practical eco-friendly access to propranolol and atenolol

Green Chemistry or Sustainable Chemistry is defined by the Environmental Protection Agency as "the design of chemical products that reduce or eliminate the use of hazardous substances" In recent years there is a greater societal expectation that chemists and chemical engineers should produce greener and more sustainable chemical processes and it is likely that this trend will continue to grow over the next few decades. This tutorial review gives information on solvents and solvent selection, basic environmental metrics collection and three industrial case histories. All three case histories involve enzymatic chemistry. Pregabalin (Lyrica®) is produced using a lipase based resolution and is extremely unusual in that all four manufacturing steps to make pregabalin are performed in water. Sitagliptin (Januvia®) uses a transaminase in the final chemical step. Finally a rosuvastatin (Crestor®) intermediate is produced using a deoxy ribose aldolase (DERA) enzyme in which two carbon-carbon bonds and two chiral centres are formed in the same process step. Show more

Modern trends in the greener synthesis and fabrication of inorganic, organic and coordination compounds, materials, nanomaterials, hybrids and nanocomposites are discussed. Green chemistry deals with synthesis procedures according to its classic 12 principles, contributing to the sustainability of chemical processes, energy savings, lesser toxicity of reagents and final products, lesser damage to the environment and human health, decreasing the risk of global overheating, and more rational use of natural resources and agricultural wastes. Greener techniques have been applied to synthesize both well-known chemical compounds by more sustainable routes and completely new materials. A range of nanosized materials and composites can be produced by greener routes, including nanoparticles of metals, non-metals, their oxides and salts, aerogels or quantum dots. At the same time, such classic materials as cement, ceramics, adsorbents, polymers, bioplastics and biocomposites can be improved or obtained by cleaner processes. Several non-contaminating physical methods, such as microwave heating, ultrasound-assisted and hydrothermal processes or ball milling, frequently in combination with the use of natural precursors, are of major importance in the greener synthesis, as well as solventless and biosynthesis techniques. Non-hazardous solvents including ionic liquids, use of plant extracts, fungi, yeasts, bacteria and viruses are also discussed in relation with materials fabrication. Availability, necessity and profitability of scaling up green processes are discussed. Show more