1,3-Disubstitutedpyrazole-4-caboxaldehyde in Heterocyclic Synthesis: A Novel Synthesis of Pyridine-2(1<i>H</i>)-thione and Fused Nitrogen and/or Sulfur Heterocyclic Derivatives
作者:Mohamed A. A. Elneairy
DOI:10.1080/10426500902814049
日期:2010.1.29
Pyridine-2(1H)-thione 5 was synthesized from the reaction of 3-[3-(4-chlorophenyl)-1-phenyl-1H-pyrazol-4-yl]-1-phenylpropenone (3) and cynothioacetamide (4). Compound 5 reacted with halogented compounds 6a–e to give 2-S-alkylpyridine derivatives 7a–e, which could be in turn cyclized into the corresponding thieno[2,3-b]-pyridine derivatives 8a–e. Compound 8a reacted with hydrazine hydrate to give 9
Pyridine-2(1H)-thone 5 由 3-[3-(4-chlorophenyl)-1-phenyl-1H-pyrazol-4-yl]-1-phenylpropenone (3) 和cynothioacetamide (4) 反应合成. 化合物 5 与卤代化合物 6a-e 反应生成 2-S-烷基吡啶衍生物 7a-e,其可以依次环化为相应的噻吩并 [2,3-b]-吡啶衍生物 8a-e。化合物 8a 与水合肼反应得到 9。后一种化合物与乙酸酐 (10a)、甲酸 (10b)、乙酸、乙酰乙酸乙酯和戊烷-2,4-二酮反应得到相应的吡啶并[3', 2':4,5]噻吩并[3,2-d]嘧啶13a,b,吡唑并[3',4':4,5]噻吩并[3,2-d]吡啶14和噻吩并[2,3- b]-吡啶衍生物分别为18和20。或者,8c与10a,b和亚硝酸反应得到相应的吡啶并[3',2':4,5]噻吩并[3,2-d]嘧啶24a