作者:Paul-Michael Windscheif、Fritz Vögtle
DOI:10.1055/s-1994-25411
日期:——
Various new 2,5-disubstituted pyridines were prepared. The 2-substituted 5-formylpyridines 8, 15a-b were obtained by reduction of the nicotinic acid 3, hydrolysis of the bis(morpholino)methylpyridine 6 or the reaction of 5-bromopyridines 12 and 14 with lithium butoxide in DMF. Dipyridylethenes 16a-b,e were synthesized by Wadsworth-Emmons reaction with pyridyl phosphonate 7 or by coupling of the aldehydes by McMurry reaction to the ethenes 16c-d. After bromination of the C=C double bond of the dipyridylethenes 16a-d, dipyridylacetylenes 18a-d were obtained via elimination of the 1,2-dipyridyl-1,2-dibromoethanes 17a-d.
合成了多种新的2,5-二取代吡啶。通过还原烟酸3、氨基二甲基吡啶6的水解或5-溴吡啶12和14与丁基锂在DMF中的反应,得到了2-取代的5-醛基吡啶8、15a-b。双吡啶乙烯16a-b,e通过Wadsworth-Emmons反应与吡啶基膦酸酯7合成,或者通过McMurry反应将醛偶联形成烯烃16c-d。在双吡啶乙烯16a-d的C=C双键溴化后,经过1,2-双吡啶-1,2-二溴乙烷17a-d的消除,得到了双吡啶乙炔18a-d。