Studies on new antiulcer agents. I. Synthesis and antisecretory activity of pyridazine derivatives.
作者:TOSHIHIRO YAMADA、YOUICHI NOBUHARA、HIROSHI SHIMAMURA、KAZUO YOSHIHARA、AZUMA YAMAGUCHI、MASAHIKO OHKI
DOI:10.1248/cpb.29.3433
日期:——
The pyridine ring of 2-phenyl-2-(2-pyridyl) thioacetamide (Ia), the lead compound for the present study, was replaced by a pyridazine ring in the hope of obtaining more potent and less toxic drugs with long-lasting action, and a series of 2-phenyl-2-(3-pyridazinyl) thioacetamide derivatives (II) was synthesized from halopyridazines (III) and phenyl-acetonitriles via the key intermediates, 2-phenyl-2-(3-pyridazinyl) acetonitrile derivatives (IV). The chemical structure of II appears to be in equilibrium between the pyridazine form and the pyridazinone-methide form on the basis of nuclear magnetic resonance (NMR) and ultraviolet (UV) spectral data. The antisecretory activity and acute toxicity of II were investigated and the structure-activity relationships are discussed. Among the compounds tested, 2-Phenyl-2-(3-pyridazinyl) thioacetamide (IIa) and 2-(6-methyl-3-pyridazinyl)-2-phenylthioacetamide (IIb) possessed long-lasting, potent activity when administered to rats at 20 mg/kg. The acute toxicities of IIa and IIb were about half to one-third of that of Ia in mice.
本研究的首要化合物2-苯基-2-(2-吡啶基)硫代乙酰胺(Ia)的吡啶环被吡嗪环替换,以期获得更具效力和更低毒性、且作用持久的药物,并合成了一系列2-苯基-2-(3-吡嗪基)硫代乙酰胺衍生物(II),这些衍生物是从卤代吡嗪(III)和苯基乙腈通过关键中间体2-苯基-2-(3-吡嗪基)乙腈衍生物(IV)合成的。根据核磁共振(NMR)和紫外(UV)光谱数据,II的化学结构似乎在吡嗪形式和吡嗪酮-美特形式之间处于平衡状态。对II的抗分泌活性和急性毒性进行了研究,并讨论了结构-活性关系。在测试的化合物中,2-苯基-2-(3-吡嗪基)硫代乙酰胺(IIa)和2-(6-甲基-3-吡嗪基)-2-苯基硫代乙酰胺(IIb)在以20 mg/kg剂量给药给大鼠时表现出持久而强效的活性。IIa和IIb的急性毒性约为Ia在小鼠中毒性的半至三分之一。