MATTHEWS, N.C.—With an eye to making chemical processes more environmentally friendly, microwave specialist CEM and the U.S. EPA recently signed a Cooperative Research and Development Agreement (CRADA) that will see the two work on scaling up common and new chemical syntheses using microwave energy. The pharmaceutical industry should be a prime benefactor.
For its part, CEM will contribute its time and expertise to the development of scale-up protocols based on research-scale chemistries developed by EPA scientists under the leadership of microwave-enhanced chemistry pioneer Dr. Rajender S. Varma.
"We appreciate [CEM's] interest in working with Dr. Varma," Gordon Evans, EPA director of sustainable technology at the National Risk Management Research Laboratory, said in announcing the CRADA. "We're looking forward to this collaborative effort...to advance the ideas of green chemistry and sustainability through the use of microwave-assisted chemical synthesis."
Dr. Michael Collins, CEM president and CEO, says his company's interest in the project also stems from CEM's decision to open a scale-up division that would see the company move microwave-enhanced chemistries from milligram to kilogram scale.
Collins sees many advantages for the pharmaceutical industry to move to greener processes, although he is unable to say exactly what kind of savings a company can make in reducing waste, a major problem in any industry.
"The financial impact will be significant, but more stringent regulations are what's really dictating the move of companies to green chemistry," he says. "Ideally, we'd like to try to eliminate solvent altogether. Microwave will allow you to go to continuous flow mode and therefore more closely approaching on-demand production, limiting the amount of materials needed at any one time and avoiding storage."
Another impetus for the application of microwave-enhanced chemistry is that for many common organic synthesis reactions, the method can improve reaction yields—for example, Biginelli condensations can see 15- to 60-percent yields increased to 90 percent. Likewise, the technology can dramatically reduce reaction times, as is the case with Heck couplings, which can move from 20-hour reactions down to 3 minutes.
Collins admits that microwave isn't a cure-all and won't necessarily work for all chemical syntheses. "The problem with microwave is that it is an expensive form of energy," he says. "Thus, we'll need to make sure the cost benefit will be there for the chemists."