Hantzsch synthesis of pyrazolo[1',2':1,2]pyrazolo[3,4-b]pyridines: partial agonists of the calcitonin receptor

J Org Chem. 2005 Jun 24;70(13):5331-4. doi: 10.1021/jo050370b.

Abstract

Small molecule calcitonin receptor agonists are of potential utility in the treatment and prevention of osteoporosis. Bicycloeneamine 1 was a useful intermediate in the synthesis of pyrazolopyridine calcitonin receptor partial agonists 2a-f. Dihydropyridines 10a-c were conveniently prepared by reaction of 1 with Knoevenagel adducts 9a-c, or in the case of 10d, by a three component reaction with 1, beta-ketoester 7b, and aldehyde 8c. Oxidation of 10a-d to pyridines 11a-d and subsequent amide formation afforded the title compounds.

MeSH terms

  • Catalysis
  • Combinatorial Chemistry Techniques*
  • Molecular Structure
  • Oxidation-Reduction
  • Pyrazoles / chemical synthesis*
  • Pyrazoles / chemistry
  • Pyrazoles / pharmacology
  • Pyridines / chemical synthesis*
  • Pyridines / chemistry
  • Pyridines / pharmacology
  • Receptors, Calcitonin / agonists*

Substances

  • Pyrazoles
  • Pyridines
  • Receptors, Calcitonin
  • pyrazolopyridine