N-(Fluoroethyl)(imidazolylphenyl)formamidines. The issue of the active species of mifentidine
作者:Arturo Donetti、Enzo Cereda、Antoine Ezhaya、Rosella Micheletti
DOI:10.1021/jm00125a006
日期:1989.5
fluorine substitution on basicity and, then, on H2-antagonist affinity in comparison with the unsubstituted N-ethyl derivative (3a), taken as a model of mifentidine. Imidazolylphenyl isothiocyanate (1), obtained by reaction of 4-(aminophenyl)imidazole with carbon disulfide and ethyl chloroformate, was condensed with the requisite 2-fluoro-substituted ethylamines to give the intermediate thioureas (2b-d)
制备了三种N-氟乙基取代的(咪唑基苯基)甲idine衍生物,即2-氟乙基(3b),2,2-二氟乙基(3c)和2,2,2-三氟乙基(3d),以测试氟的效果与未取代的N-乙基衍生物(3a)相比,在碱性上进行取代,然后在H2-拮抗剂亲和力上进行取代,以此作为米芬太定的模型。将4-(氨基苯基)咪唑与二硫化碳和氯甲酸乙酯反应制得的咪唑基苯基异硫氰酸酯(1)与必需的2-氟取代的乙胺缩合,得到中间体硫脲(2b-d)。通过阮内镍对这些硫脲进行脱硫,得到了所需的甲am(3b-d)。发现增加的氟取代实质上降低了甲ami基的碱性(3a,pKa = 8.65; 3b,pKa = 8.12; 3c,pKa = 6.60; 3d,pKa = 6。14),同时对咪唑部分有适度的作用。根据对豚鼠心房的组胺刺激的变时反应的拮抗作用评估,H2受体的亲和力在氟取代后有所增加(3a,KB = 177; 3b,KB = 61; 3c,KB