Exploring the role of bromine at C(10) of (+)-4-[2-[4-(8-chloro-3,10-dibromo- 6,11-dihydro-5H-benzo[5,6]cyclohepta[1,2-b]pyridin-11(R)-yl)-1-piperidinyl]-2- oxoethyl]-1-piperidinecarboxamide (Sch-66336): the discovery of indolocycloheptapyridine inhibitors of farnesyl protein transferase

J Med Chem. 2002 Aug 29;45(18):3854-64. doi: 10.1021/jm010463v.

Abstract

The 10-bromobenzocycloheptapyridyl farnesyl transferase inhibitor (FTI) Sch-66336 (1) is currently under clinical evaluation for the treatment of human cancers. During structure-activity relationship development leading to 1, 10-bromobenzocycloheptapyridyl FTIs were found to be more potent than analogous compounds lacking the 10-Br substituent. This potency enhancement was believed to be due, in part, to an increase in conformational rigidity as the 10-bromo substituent could restrict the conformation of the appended C(11) piperidyl substituent in an axial orientation. A novel and potent class of FTIs, represented by indolocycloheptapyridine Sch-207758 [(+)-10a], have been designed based on this principle. Although structural and thermodynamic results suggest that entropy plays a crucial role in the increased potency observed with (+)-10a through conformational constraints and solvation effects, the results also indicate that the indolocycloheptapyridine moiety in (+)-10a provides increased hydrophobic interactions with the protein through the addition of the indole group. This report details the X-ray structure and the thermodynamic and pharmacokinetic profiles of (+)-10a, as well as the synthesis of indolocycloheptapyridine FTIs and their potencies in biochemical and biological assays.

MeSH terms

  • Alkyl and Aryl Transferases / antagonists & inhibitors*
  • Animals
  • Antineoplastic Agents / chemical synthesis*
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology
  • Bromine / chemistry*
  • Crystallography, X-Ray
  • Enzyme Inhibitors / chemical synthesis*
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacology
  • Half-Life
  • Indoles / chemical synthesis*
  • Indoles / chemistry
  • Indoles / pharmacology
  • Mice
  • Mice, Nude
  • Models, Molecular
  • Piperidines / chemical synthesis*
  • Piperidines / chemistry
  • Piperidines / pharmacology
  • Pyridines / chemical synthesis*
  • Pyridines / chemistry
  • Pyridines / pharmacology
  • Structure-Activity Relationship
  • Thermodynamics

Substances

  • Antineoplastic Agents
  • Enzyme Inhibitors
  • Indoles
  • Piperidines
  • Pyridines
  • Alkyl and Aryl Transferases
  • p21(ras) farnesyl-protein transferase
  • lonafarnib
  • Bromine