Where does aspirin come from?

[Caliban]

Yeah, yeah, I know. Willow bark. I’m talking about the stuff in my medicine cabinet. Are there actually huge willow farms out there where the bark is harvested to make aspirin? Or can the chemical be synthesized on its own?

If that question proves too easy to answer, how about other OTC pain relievers like ibuprofen or tylenol? Where the heck do they come from?

And suppose I’m walking through the forest, trying to work off a serious hangover, when I spy a willow tree. Approximately how much of the bark would I need to consume in order to get an active dose (let’s say 500 mg)?

[SmackFu]

What?! You didn’t make aspirin in high school chemistry? What is the world coming to? Here’s the scoop:

1.Heat a 250 mL beaker of water to 70 to 80 degrees C.
2.Measure and record an approximate 1 g sample of salicylic acid. Place it, along with 2 mL of acetic anhydride and one drop of 85% phosphoric acid, in a 25 x 150 mm test tube.
3.Warm the test tube and mixture in a hot water bath (70 to 80 degrees C) and stir until a clear solution is formed. Warm for a total of 15 minutes.
4.Carefully add 10 mL of deionized water. An oily layer will separate. Stir the cloudy mixture until a clear solution forms. Continue to heat for a total of 5 minutes.

Of course, at that point it’s still mixed with acetic acid, so it needs a few more steps that aren’t worth reproducing.

Now in high school they never told us where the salicylic acid came from. Maybe that still comes from willow bark?

[Osakadave]

Here’s a link to an in depth look at the manufacture of asprin: http://www.webspan.net/~jlipuma/ap1.htm. I’ve scanned it and didn’t find the root source of the salicylic acid used to synthesize asprin. I have made an inquery to Bayer. We’ll see what happens.

[rowrrbazzle]

A Google search turned this up - http://www.bartleby.com/65/sa/salicyli.html

Salicylic acid, or 2-hydroxybenzoic acid, C[SUB] 6[/SUB]H[SUB]4/SUBCO[SUB]2[/SUB]H, a colorless, crystalline organic carboxylic acid that melts at 159ºC; it is soluble in ethanol and ether but is only slightly soluble in water. It is prepared commercially by heating sodium phenolate (the sodium salt of phenol) with carbon dioxide under pressure to form sodium salicylate, which is treated with sulfuric acid to liberate salicylic acid.

[SmackFu]

Good find zgystardst, I was just about to post that link…

Anyways, apparently they used to just take the salicylic acid as is, without combining it with the acetate. It had some side-effects though: “the compound’s acidic properties caused irritation in the moist membranes of the mouth, throat and stomach.” And it tasted sour. So some guy who worked at Bayer figured out that if you followed another 10-15 steps, you could solve all those problems.

And here are the steps for ibuprofen: http://www.wcer.wisc.edu/step/ep301/Spr2000/esselman/IBUc.html. It’s a pretty modern drug. First synthesized in the 60’s, and only available OTC since the early 80’s.