Harmful Greenhouse Gas Turned Into Tool for Making Pharmaceuticals

http://www.sciencedaily.com/releases/2012/12/121206142023.htm

Harmful Greenhouse Gas Turned Into Tool for Making Pharmaceuticals: New Technique Finds Use for Ozone-Destroying Chemical Waste Product

ScienceDaily (Dec. 6, 2012) — A team of chemists at USC has developed a way to transform a hitherto useless ozone-destroying greenhouse gas that is the byproduct of Teflon manufacture and transform it into reagents for producing pharmaceuticals.

Because of the popularity of Teflon, which is used on everything from cooking pans to armor-piercing bullets, there's no shortage of its waste byproduct, fluoroform. Major chemical companies such as DuPont, Arkema and others have huge tanks of it, unable to simply release it because of the potential damage to the environment. Fluoroform has an estimated global warming potential 11,700 times higher than carbon dioxide.

But one man's trash is another man's treasure, and G.K. Surya Prakash -- who has spent decades working with fluorine reagents -- saw the tanks of fluoroform as an untapped opportunity.

Prakash, a professor of chemistry at the USC Dornsife College of Letters, Arts and Sciences and director of the USC Loker Hydrocarbon Research Institute, describes fluorine as "the kingpin of drug discovery." About 20 to 25 percent of drugs on the market today contain at least one fluorine atom.

Fluorine can be found in all different kinds of drugs, everything from 5-Fluorouracil (a widely used cancer treatment discovered by Charles Heidelberger at USC in the '70s) to Prozac to Celebrex.

"It's a small atom with a big ego," he said, referring to the fact that while fluorine is about the same size as a tiny hydrogen atom -- so similar that living cells cannot tell the two elements apart -- it is also extremely electronegative (that is, it has a strong attraction for electrons) making carbon-fluorine chemical bond quite strong, which improves the bioavailability of drugs made with fluorine.

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