Jump to content


Senior Members
  • Posts

  • Joined

  • Last visited

Everything posted by Knumbnuts

  1. Try using a basic ion-exchange resin or better perhaps proton sponge. http://en.wikipedia.org/wiki/1,8-Bis(dimethylamino)naphthalene
  2. Do you mean these? http://www.dpd-tablet.co.uk
  3. The main use of this medication is in operating suites and critical care where pain relief is required for a short period of time. It also offers properties of sedation and this makes it a good analgesic component. You need a much higher dose of morphine for the same effect. I was on morphine for pain treatment, after a while I developed a tolerance to it and had to change to Fentaynl. None of these drugs are very pleasant whatsoever.
  4. It is only administered under the supervision of health care professionals and is an analgesic.
  5. No, I would not expect them to be the same. In one case the H is axial, in the other equatorial. And it is in different magnetic environments. So different spectra.
  6. You are correct in saying they have different physical properties, isn't being able to be distinguished by their spectra using just that property? The functional groups may be the same but they are arranged differently along a given carbon backbone. Therefore they are in different chemical and physical environments.
  7. You may be better putting this mixture through a GC.
  8. Did anyone see the remarkable paper in Nature by Inokuma etal, entitled X-Ray analysis on the nanogram to microgram scale using porous complexes; Nature 2013, 495, 461-466 doi:10.1038/nature11990. Apparently all you have to do is dip your sample in a solution of the porous material, slowly evaporate the solvent and place the solid material in the X-ray diffractometer, you know the one, it's been gathering dust in the corner of the lab. Out pops a single crystal structure showing the guest/host complex in which the guest can clearly be observed. The authors have also combined this with HPLC methodology. This is an amazing piece of work. I wish it had been around earlier because the effort required to obtain a single crystal suitable for X-ray was sometimes, in fact most of the time, enormous. I think it will change the field of structure determination, particularly that of natural products, beyond imagination, and may even make NMR obsolete (assuming you can afford a diffractometer and a tame crystallographer to work it). Imagine running your HPLC scale reaction, separating the products and obtaining an (almost) immediate X-ray structure of all the reaction products.
  9. Here is an Org. Syn. prep. http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1p0077
  10. The first filtration is to remove salts. You then take the filtrate (the liquid in the flask) and remove the acetone. The residue left after this evaporation is dissolved in ethyl acetate and washed to remove any further salts. You add magnesium sulphate to dry the ethyl acetate/product solution and remove the magnesium sulphate by filtration. The filtrate is then evaporated to remove the ethyl acetate and the residue chromatographed.
  11. How can it be 69 protons? 68 or 70 would make more sense. It must be a solvent peak, hexane or what ever you used to extract the natural product.
  12. What solvent did you use for the H-NMR?
  13. How do you know your oil contains capsaicin? If it does then I would not use any I made for consumption.
  14. I would guess that this is probably the case as the WIKI says it polymerises in the presence of nucleophiles for example, water. http://en.wikipedia.org/wiki/Cyanoacrylate But that it actually smokes and bursts into flame, that is extreme and good to know.
  15. Treat the mixture with aqueous sodium hydroxide. This should hydrolyse the anhydride and leave the acids as their sodium salts. These should be soluble in water, and after an extraction of the basic solution with an organic solvent, which is not miscible with water, you should have your diketone in the organic layer. Separate the layers and then evaporation of the solvent will deliver the diketone, hopefully pure enough that it crystallises.
  16. Treat the mixture with base, hydrolyse the anhydride, remove as the sodium salt by extraction into water. Crystallise the diketone from the organic phase.
  17. What is the anhydride of an aromatic diketone? Perhaps you could elaborate.
  18. Well isopropyl is a recognised IUPAC fragment, ChemDraw gives this compound as 4-isopropyl-2,6,6-trimethylnonane
  19. According to the equation 0.038 mol toluene should produce 0.038 mol nitrotoluene. You obtained 0.026mol nitrotoluene, so what is the actual yield in % and what is the theoretical yield in grams of nitrotoluene?
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.