二氢和四氢苯骈二氮杂的~1H NMR研究

~1H NMB Study of Some 2, 4-Disubstituted 1, 5-Benzodiazepines

用质子同核去偶,亚谱分析,SIMEQ自旋模拟顺序,Karplus方程和同系物比较等方法和技术,对五个二氢苯骈二氮杂(艹卓)化合物Ⅰ和十个四氢苯骈二氮杂(艹卓)化合物Ⅱ进行了~1H NMR系统研究。确定了高熔点的四氢化合物Ⅱ(H)为椅型构象,低熔点的四氢化合物Ⅱ(L)为扭船型构象。二氢化合物Ⅰ为类船型结构。 本文还报导了Ⅰ_c,Ⅱ_c(H),Ⅱ_c(L)化合物中的H_a,H_b质子的自旋模拟值和实验值,得到了较为满意的结果。

A systematic study by proton NMR of five dihydro-(Ⅰ) and ten tetrahydro-(Ⅱ) benzodiazepines is reported. The ten tetrahydro-compounds(Ⅱ) are composed of five pairs of isomeis, Ⅱ(L) andⅡ(H).With the help of the techniques of proton-proton homonuclear decoupling, sub-spectral analysis, SIMEQ spin simulation program, the applications of Karplus equation and the comparison of series of analogous compounds, the chemical shifts and coupling constants of protons on 7-membered heterocyclic rings and the orientation of cer- tain groups in space have been determined. It is suggested that the high-melting-point tetrahydro-compounds Ⅱ(H) assume the chair conformation, while the low-melting-point tetrahydro-compounds Ⅱ(L) exist in the twist-boat conformation. The dihydro-com-pounds(Ⅰ) are found to be the boatlike structures. This is supported by an examination of stick-ball molecule models.Experimental and simulation values of H(a), H(b) on compounds Ⅰc, Ⅱc(L), Ⅱc (H) are reported, good agreement is observed.