Based on the X-ray crystallography and 1H NMR spectroscopy data and quantum chemical studies, it was found that 1(11)H-2, 3, 4, 5-tetrahydro[1, 3]diazepino[1, 2-a]benzimidazole (1) exists almost exclusively in the 1H-prototropic form. To prepare the fixed 11H-diazepinobenzimidazole forms of 1, 1-R-2-(4-chlorobutylamino)benzimidazoles (R = Me, N=CHAr) were synthesized, which underwent thermal cyclization with the formation of a mixture of 11-Rsubstituted diazepine 1 and 1-R-2-(pyrrolidin-1-yl)benzimidazole. Alkylation of diazepine 1 in a neutral medium regioselectively gave 11-R-diazepinobenzimidazoles in high yield. Their 1-substituted isomers were obtained by carrying out this reaction in the system NaH—THF. The N(11)-derivatives of diazepinobenzimidazole 1 were found to inhibit dipeptidyl peptidase 4 (DPP-4), but less actively than a comparator drug sitagliptin. The compounds under study did not exhibit antiglycation action in vitro and virtually did not affect activity of α-glucosidase and glycogen phosphorylase. However, they are characterized by a strong antiaggregant effect, making these derivatives promising for further studies.
基于X射线晶体学、1H NMR光谱数据和量子
化学研究,发现1(11)H-2,3,4,5-四氢[1,3]二氮杂环[1,2-a]
苯并咪唑(1)几乎完全以1H-质子化形式存在。为了制备固定化的11H-二氮杂环
苯并咪唑形式1,合成了1-R-2-(4-
氯丁胺)
苯并咪唑(R=Me,N=CHAr),它们经过热环化反应,形成11-R取代的二氮杂环1和1-R-2-(
吡咯烷-1-基)
苯并咪唑的混合物。二氮杂环1在中性介质中的烷基化反应选择性地得到高产率的11-R-二氮杂环
苯并咪唑。它们的1-取代异构体是通过在NaH-THF体系中进行此反应得到的。发现二氮杂环
苯并咪唑1的N(11)衍
生物抑制二肽基肽酶4(
DPP-4),但活性低于对照药物
西他列汀。所研究的化合物在体外未表现出抗糖基化作用,并且几乎不影响α-
葡萄糖苷酶和
糖原磷酸化酶的活性。然而,它们的特点是具有强大的抗聚集作用,使这些衍
生物有望进一步研究。