Clay for green chemistry
doi:10.1038/nindia.2009.6 Published online 19 January 2009
A marine clay from Tuticorin in southern India is poised to show the 'green route' for synthetic chemists. Scientists in Hyderabad have found for the first time that this clay, called chamosite, can be used as a reusable catalyst in 'acylation', a process used for synthesis of a variety of organic compounds including drugs like aspirin, nitroglycerine, chloramphenicol and sulphanilamides1.
Acylation is usually carried out by treatment of alcohols or amines (organic compounds containing Nitrogen) with acetyl chloride or acetic anhydride in the presence of a catalyst in an organic solvent. Existing catalysts do not satisfy the requirements of green synthesis as they cannot be recovered or reused and have to be disposed of carefully.
"One of the current challenges is to develop synthetic methods that are less polluting," says B. Sreedhar, lead author of the study. "We found that, the Tuticorin clay, serves as an efficient and reusable, heterogenous catalyst for the acylation of alcohols and amines," he says. The process is reasonably fast and clean without any side products and it is now possible to do "environmentally benign green chemistry both at industrial level and laboratory scale", he says.
The authors of this work are from: Indian Institute of Chemical Technology IICT, Hyderabad, India & National Geophysical Research Institute, Hyderabad, India.
- Sreedhar, B. et al. Highly efficient heterogeneous catalyst for acylation of alcohols and amines using natural ferrous Chamosite. Appl. Clay Sci. doi: 10.1016/j.clay.2008.10.001 (2008)