Synthesis and β-adrenergic blocking activity of 1,4-benzothiazine oxime ethers

Synthesis of 6-, 7-, 8-acetimidoyloxypropanolamines of 3,4-dihydro-3-oxo-2 H-1,4-benzothiazine and 8-iminoxypropanolamines of 3,4,5,6,7,8-hexahydro-3-oxo-2 H-1,4-benzothiazine are reported. All of the synthesized compounds were tested in vitro for their ability to displace [3H]dihydroalprenolol from turkey erythrocyte membranes and in vivo for their β-adrenoceptor blocking activity by the inhibition of isoprenaline-induced tachycardia and compared with the corresponding oxypropanolamines which we had previously described as β-blockers