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In this reaction, what are the ideal circumstances? ttt

  1. Which base would be a great choice?
  2. How much time does it take for tryptophan to fully decarboxylate?
  3. What is the ideal temperature for this type of reaction?
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Just heating with base is ineffective. Laval and Golding [1] describe a general procedure for the decarboxylation of α-amino acids using N-bromosuccinimide and Ni(0) in aqueous solution. The yields are pretty good.

Reference

  1. Laval, G.; Golding, B. T. One-Pot Sequence for the Decarboxylation of α-Amino Acids. Synlett 2003, No. 4, 0542–0546. DOI: 10.1055/s-2003-37512.
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    $\begingroup$ Thank you, btw heating with base why doesn't effective? What would happen to tryptophan? $\endgroup$
    – ostal123
    Jan 18 '18 at 13:21
  • $\begingroup$ I think you would just get a very hot soln of the sodium salt of tryptophan. $\endgroup$
    – Waylander
    Jan 18 '18 at 14:06
  • $\begingroup$ I added a complete reference; however, it doesn't look like authors mention Ni(0) at all, instead they used nickel(II) dichloride hexahydrate. IMO it would be beneficial for others if there were a bit more details from the paper itself, including reaction schemes and the reported yields (authors give exact numbers for each reaction, not just "pretty good"). Otherwise it leaves an impression that the paper haven't been read beyond the abstract. $\endgroup$
    – andselisk
    Jul 12 at 20:43
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    $\begingroup$ The authors use Nickel(II) Chloride plus sodium borohydride which generates Ni(0) in situ $\endgroup$
    – Waylander
    Jul 12 at 21:02
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    $\begingroup$ The reaction of Laval is two steps. NBS effects oxidative decarboxylation and oxidation of the resultant imine to a nitrile. NiCl2/NaBH4 effects reduction of the nitrile to an amine. $\endgroup$
    – user55119
    Jul 13 at 19:30

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