WILMINGTON, Del., Sept. 5 (UPI) -- After years of research, scientists in Delaware have discovered a new way of making key building blocks for many modern medicines, a breakthrough over century-old techniques that inadvertently generate acids and other toxic waste.
"The only byproduct of our reaction is water," researcher Mas Subramanian, a materials scientist at DuPont Central Research and Development, told United Press International.
This simple, clean technique is not only environmentally friendly, but also promises to drive down costs, the researchers said.
"This is a real advance, and I think it has a very significant future," comment chemist William Dobier of the University of Florida in Gainesville.
The technique uses fluorine, the element best known for fighting cavities that also plays a pivotal role in modern medicine. Some 30 percent to 50 percent of all pharmaceuticals now contain fluorine, Dobier told UPI, because it helps boost their effectiveness.
Scientists developed ways to insert fluorine into organic chemicals a century ago, and with a few modifications these widely used methods remain in use in industry today. However, "These processes often involve many steps that generate large amounts of waste at each step," Subramanian explained, including hydrochloric acid. Cleaning up this waste can prove quite expensive.
Subramanian and his colleague Leo Manzer discovered a greener alternative that adds fluorine to the common organic compound benzene in only one step. "I didn't expect this to work so well," Subramanian said.
Scientists for years have looked for organic methods to add fluorine to chemicals. After three years of tinkering, Subramanian and Manzer found an inorganic chemical to carry out the job instead. The compound in question is called copper fluoride and is quite cheap, Subramanian said.
The technique removed hydrogen from benzene and replaces it with fluorine. The freed hydrogen then combines with easily available oxygen to become water. After tinkering with a variety of chemicals for three years, the researchers found copper fluoride carried out the task with extreme efficiency.
So far, the new technique has created organic compounds known as fluorinated aromatics, often used in making drugs and farm-used fungicides. Dobier, who is continuing work on Subramanian and Manzer's findings with the help of two donated patents from DuPont, said it is likely that similar techniques can make a wider range of fluorinated organic chemicals in the future.
"Of course we have to optimize this for an industrial route," Subramanian said. "This is only a laboratory demonstration. But we can probably try doing this in six months to one year."
The scientists describe their findings in the September 6 issue of the journal Science.
(Reported by Charles Choi, UPI Science News, in New York)
