Intramolecular Diels-Alder reactions of 1,2,4-triazines. Synthesis of 3-alkylpyridines via Raney nickel desulfurization of thieno[2,3-b]pyridines
作者:Maria V. Papadopoulou、Edward C. Taylor
DOI:10.1016/j.tet.2021.132158
日期:2021.6
2-Aryl-2,3-dihydrothieno[2,3-b]pyridines have been prepared via intramolecular Diels-Alder reactions of suitably 3-substituted 1,2,4-triazine intermediates, followed by their reductive desulfurization with Raney Nickel to form 3-substituted pyridines. A one-pot synthesis of 2-aryl-2,3-dihydrothieno[2,3-b]-pyridines from thiosemicarbazide is described as well.
2-芳基-2,3-二氢噻吩并[2,3-b]吡啶是通过适当的3-取代1,2,4-三嗪中间体的分子内Diels-Alder反应制备的,然后用雷尼镍还原脱硫形成3-取代的吡啶。还描述了从氨基硫脲一锅法合成 2-芳基-2,3-二氢噻吩并[2,3-b]-吡啶。