Patent for IITM scientist for green methodology to produce key chemical

A scientist at the Department of Chemistry, Indian Institute of Technology, Madras, has been granted a patent for developing a green methodology for producing a medicinally important compound called Benzo[b]thiophene.

Dr E. Poonguzhali, who works under the Women Scientists Scheme (WOS-A) of the Department of Science & Technology, has earned the patent number 384111 (Date of Grant: December 10, 2021) with patentee Indian Institute of Technology, Madras, a release from the Ministry of Science & Technology said on Friday.

The compound Benzo[b]thiophene is present in a range of medicines such as raloxifene (used in osteoporosis), zileuton (used in asthma), and sertaconazole (antifungal medication) and the one-step synthesis of the 2-substituted benzo[b]thiopheneAcan replace hazardous industrial production of the compound.

Currently, available synthesis methods of the compound give yields ranging from good to excellent, but these are not environmentally friendly. Besides, it involves the use of very high temperatures.

Apart from this, the reactions are carried out in closed vessels exposing the process to the risk of explosion, use of OLED lights required in the reaction increased the cost of the process, and the various steps involved need close monitoring while the metal catalyst needed for it is toxic in nature.

Dr Poonguzhali has successfully transferred commercially available starting materials to medicinally important 2-acylbenzo[b]thiophenes in the presence of copper acetate and tetrabutylammonium chloride catalytic system in water medium and open-air atmosphere at room temperature.

Elaborating on the science behind the mechanism, Dr Poonguzhali said that as water is the medium, there is no need for organic solvent. Besides, there is no air pollution. Room temperature saves energy, and directly transferring the commercially available starting materials to medicinally essential building blocks in a one-pot manner saves workforce, energy and space.

"My family had encouraged me to invent green methodology to replace the hazardous methods. When I started my research career with DST support, I designed the green methodology with the help of Prof. G. Sekar and Prof. Ramesh L. Gardas and succeeded in synthesising the medicinally important compounds," she said.

A single mother, she adds: "My life revolves around my son and my research. My son's support has helped me overcome the difficulties I have encountered so far and spend time on my research."