Were can you buy the chemical formula c9h13n?

Answer 1

You want to buy the chemical formula? Right here, I'll sell it to you for $20. Thank you, feel free to use that chemical formula as much as you like.

However, I suspect you mean you want to buy the chemical represented by that formula, and the problem is that that formula doesn't represent a specific chemical. There are many possible ways to arrange those atoms into a compound (I did a quick search, and found 65 different ones that I could buy, and that's not counting those that aren't commercially available), and we have no idea which of them you mean (well ... I have someidea; I suspect you mean the illegal one, alpha-methylphenylethylamine, better known by its contracted name, amphetamine).

Actually, it's even possible to legally buy that one, provided you have what the government considers a valid reason for doing so. Which you don't, because if you did, you would have given us the IUPAC name or structural formula and you'd probably also have a very good idea of what suppliers sell things of that nature.