Regioselective synthesis of 2- and 5-trifluoromethyl-or 2- and 5-difluoromethylpyrazolo[1,5-c]pyrimidines based on 7,7,7-trifluoro-or 7,7-difluoro-2,4,6-trioxoheptanoic and 6-trifluoromethyl-or 6-difluoromethylcomanic acids
作者:B. I. Usachev、D. L. Obydennov、V. Ya. Sosnovskikh
DOI:10.1007/s11172-012-0212-5
日期:2012.8
6-Tri- and 6-difluoromethylcomanic acids and their ethyl esters reacted with aminoguanidine, predominantly giving 5-RF-pyrazolo[1,5-c]pyrimidines, whereas the reaction of the openchain synthetic equivalents, i.e., ethyl 7,7,7-trifluoro- and 7,7-difluoro-2,4,6-trioxoheptanoates, with this polynucleophile allowed us to obtain regioselectively 2-RF-pyrazolo[1,5-c]pyrimidines.
6-三氟和 6-二氟甲基烟酸及其乙酯与氨基胍反应,主要生成 5-RF-吡唑并[1,5-c]嘧啶,而开链合成等价物,即7,7,7-三氟和 7,7-二氟-2,4,6-三氧代庚酸乙酯与这种多核亲和剂的反应,使我们能够获得具有区域选择性的 2-RF-吡唑并[1,5-c]嘧啶。