Abstract
With the aim of improving of the efficacy and decreasing the side effects of oxybutynin (1), N-[(tetrahydro-3- or 4-pyridyl)methyl]-, N-(4-piperidyl)-, and N-(3- or 4-piperidylalkyl)-2-hydroxyacetamides (3a-n, 4a-g) and the related carboxamides (3o-r, 4h-k, 13', 17) were synthesized and evaluated for inhibitory activity against urinary bladder rhythmic contraction in rats and for mydriatic activity in rats. Some of these compounds were superior to oxybutynin in both inhibitory activity against bladder contraction and selectivity between inhibitory activity against bladder contraction and mydriatic activity. Among them, N-[(1, 2, 3, 6-tetrahydro-4-pyridyl)methyl]- and N-[(1, 2, 3, 6-tetrahydro-1-methyl-4-pyridyl)methyl]-2-hydroxy-2, 2-diphenylacetamide (3e, 3f) exhibited the most potent inhibitory acitivity against bladder contraction (ED30=0.005 and 0.003 mg/kg i.v., respectively). Judging from the effect of 3e on detrusor contraction in vitro in guinea-pigs, it appeared that the inhibitory activity of 3e against bladder contraction in vivo was related mainly to its inhibitory activity against detrusor contraction in vitro induced with carbacol (antimuscarine-like activity). The selectivity (20-fold) of 3e between inhibitory activity against bladder contraction and mydriatic activity was greatly superior to that (0.48-fold) of oxybutynin.Compound 3e was synthesized by debenzylation (method E or F) of the corresponding N-[[1-(4-methoxybenzyl)-tetrahydro-4-pyridyl]methyl] derivative (3k), which was prepared by acylation (method B) of the corresponding (tetrahydro-4-pyridyl)methylamine (7k) or by reduction (method D) of the corresponding pyridinium chloride (14k) with NaBH4.
