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Thiazoles

Aldrich ChemFiles 2007, 7.8, 5.

Aldrich ChemFiles 2007, 7.8, 5.

2,4-Dibromothiazole has been gaining increasing popularity as a building block in the synthesis of several interesting targets. Bach and co-workers have reported the regioselective metalation of this building block in a route to furnish the eastern fragment of the thiazole peptide GE2270 A (Scheme 1).1

Scheme 1(677914)

A formal enantioselective approach to (–)-mycothiazole was described which began with the chemoselective substitution of the bromine at the 2-position in 2,4-dibromothiazole (Scheme 2).2 The racemic product was achieved with an overall yield of 5% over 18 steps. Similarly, Panek reported regioselective Negishi cross-coupling at the 2-position in his total synthesis of cystothiazoles A and B (Scheme 3).3

Scheme 2(677914)

Scheme 3(677914)

Several groups have reported the use of 2-amino-4,5,6,7- tetrahydrobenzothiazole in the synthesis of various inhibitors.4 Most recently, Kraus, Maina, and co-workers have developed several pifithrin-a analogues from 2-amino-4,5,6,7- tetrahydrobenzothiazole (Scheme 4).4a These analogues are potent p53 inhibitors, and could prove effective in therapies for various neurodegenerative disorders.

Scheme 4(685372)

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Materials

     

References

  1. Delgado, O. et al. J. Org. Chem. 2006, 71, 4599.
  2. Le Flohic, A. et al. Org. Lett. 2005, 7, 339.
  3. Shao, J.; Panek, J. S. Org. Lett. 2004, 6, 3083.
  4. (a) Pietrancosta, N. et al. J. Med. Chem. 2006, 49, 3645. (b) Barchéchath, S. D. et al. J. Med. Chem. 2005, 48, 6409. (c) Costanzo, M. J. et al. J. Med. Chem. 2005, 48, 1984.

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