Compounds represented by the formula ##SPC1## Wherein R.sup.1 is a pyridyl, R.sup.2 is hydrogen or lower alkyl, R.sup.3 is hydrogen, lower alkyl or benzyl and R.sup.4 is phenyl or phenyl substituted at one or more carbon atoms with one or more of halogen, lower alkyl, lower alkoxy, nitro or amino and pharmaceutically acceptable acid addition salts thereof, having analgesic activity are disclosed.