作者:Dmitrii V. Sevenard、Oleg G. Khomutov、Olga V. Koryakova、Valeriya V. Sattarova、Mikhail I. Kodess、Johannes Stelten、Ildiko Loop、Enno Lork、Kazimir I. Pashkevich、Gerd-Volker Röschenthaler
DOI:10.1055/s-2000-8200
日期:——
2-Acylcycloalkanones having polyfluoroalkyl groups react with guanidine, urea, thiourea, methylisothiourea, benzamidine, guanylthiourea, dicyanodiamide, and trifluoroacetylurea by Lewis-acid catalysis to form the corresponding 5,6-oligomethylene pyrimidines. A decrease in the yields along with increase of polyfluoroalkyl substituent length in the molecule of the starting 1,3-diketone was observed in the case of reagents with lower nucleophilicity (urea, thiourea, dicyanodiamide). The pyrimidines obtained from aromatic aldehydes showed E-configuration with respect to the arylidene double bond. Tautomeric structures as a function of the substituent in 2 position in the pyrimidine ring both in liquid and solid state were investigated by X-ray diffraction, IR and NMR spectroscopy.
含有多氟烷基团的2-酰基环烷酮与胍、尿素、硫脲、甲基异硫脲、苯基胍、氨基硫脲、二氰二胺和三氟乙酰尿素在路易斯酸催化下反应,形成相应的5,6-聚甲烯基嘧啶。观察到随着起始1,3-二酮分子中多氟烷基取代基长度的增加,对于核能性较低的试剂(如尿素、硫脲和二氰二胺),产率下降。由芳香醛获得的嘧啶相较于芳基烯烃双键显示E-构型。通过X射线衍射、红外光谱和核磁共振光谱研究了嘧啶环中2位取代基的变化对其互变异构体结构的影响,涉及液态和固态。