N-substituted dibenzoxazepines as analgesic PGE2 antagonists

8-Chlorodibenz[b,f][1,4]oxazepine-10(11H)-carboxylic acid, 2-acetylhydrazide (1, SC-19220) has been previously reported by us and others to be a PGE 2 antagonist selective for the EP 1 receptor subtypes with antinociceptive activities. 2 Analogs of SC-19220, in which the acetyl moiety has been replaced with pyridylpropionyl groups and their homologs, have been synthesized as illustrated by compounds 13 and 29. These and other members of this series have been shown to be efficacious analgesics and PGE 2 antagonists of the EP 1 subtype. This report discusses the structure activity relationships within this series