A new protocol to synthesize 1,4-dihydropyridines by using 3,4,5-trifluorobenzeneboronic acid as a catalyst in ionic liquid: synthesis of novel 4-(3-carboxyl-1H-pyrazol-4-yl)-1,4-dihydropyridines
作者:Radhakrishnan Sridhar、Paramasivan T. Perumal
DOI:10.1016/j.tet.2005.01.008
日期:2005.2
liquid mediated facile synthesis of 4-pyrazolyl 1,4-dihydropyridines at room temperature by the cyclocondensation of ethyl 3-aminocrotonate, pyrazole aldehyde and a β-keto ester is reported. The procedure adopted was found to be eco-benign, facile at room temperature and better than the conventional, [bmim]Cl mediated and InCl3 catalysed, [bmim]Cl mediated 1,4-dihydropyridine syntheses.
据报道,在3,4,5-三氟苯硼酸催化下,离子液体介导的3-氨基巴豆酸乙酯,吡唑醛和β-酮酯的环缩合反应在室温下容易地合成4-吡唑基1,4-二氢吡啶。发现所采用的方法是生态友好的,在室温下容易,并且比常规的[bmim] Cl介导的和InCl 3催化的,[bmim] Cl介导的1,4-二氢吡啶合成更好。