Synthesis and anticonvulsant activity of enaminones. 2. Further structure-activity correlations

J Med Chem. 1993 Jul 9;36(14):1947-55. doi: 10.1021/jm00066a003.

Abstract

This report continues the in-depth evaluation of methyl 4-[(p-chlorophenyl)amino]-6-methyl-2-oxocyclohex-3-en-1-oate , 1 (ADD 196022), and methyl 4-(benzylamino)-6-methyl-2-oxocyclohex-3-en-1-oate, 2, two potent anticonvulsant enaminones. These compounds were evaluated employing the amygdala kindling model. Neither 1 nor 2 was active against amygdala kindled seizures, further supporting the corneal kindled model as a definitive tool for antielectroshock seizure evaluation as previously reported. Additional intraperitoneal (ip) data on 1 revealed toxicity at 24 h at 100 mg/kg. Several active analogs have been prepared with the view to minimizing toxicity. In a special ip rat screen developed by the Antiepileptic Drug Development (ADD) Program, these newer analogs were evaluated for protection against maximal electroshock seizures (MES) at 10 mg/kg and neurotoxicity at 100 mg/kg. From this screen, several compounds were shown to be safer alternatives, the most notable was methyl 4-[(p-bromophenyl)amino]-6-methyl-2-oxocyclohex-3-en-1-oate, 13. Compound 13 had an ip ED50 of 4 mg/kg in the rat and a TD50 of 269 mg/kg, providing a protective index (TD50/ED50) of > 67. By variation in the ring size, additional aromatic substitutions and the synthesis of acyclic analogs, these newer compounds provide a more definitive insight into the structure-activity correlation. CLOGP evaluation and molecular modeling studies are also provided to further elaborate the molecular characteristics of potential anticonvulsant enaminones.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Anticonvulsants / chemical synthesis*
  • Anticonvulsants / chemistry
  • Anticonvulsants / pharmacology*
  • Benzylamines / chemical synthesis*
  • Benzylamines / chemistry
  • Benzylamines / pharmacology
  • Cyclohexanecarboxylic Acids / chemical synthesis*
  • Cyclohexanecarboxylic Acids / chemistry
  • Cyclohexanecarboxylic Acids / pharmacology
  • Cyclohexylamines*
  • Kindling, Neurologic / drug effects
  • Male
  • Mice
  • Models, Molecular
  • Rats
  • Rats, Sprague-Dawley
  • Seizures / drug therapy*
  • Structure-Activity Relationship

Substances

  • Anticonvulsants
  • Benzylamines
  • Cyclohexanecarboxylic Acids
  • Cyclohexylamines
  • ADD 196022
  • methyl 4-(benzylamino)-6-methyl-2-oxocyclohex-3-en-1-oate