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报道了七种 1-苯甲酰基 - 4,4-二烷基哌嗪溴化物的 1 H和 1 3C NMR,并对全部谱峰进行了归属 ,初步讨论了影响 1 H NMR,1 3C NMR化学位移的因素 .结果发现 :1)受苯甲酰基和 R1 ,R2 的影响 ,当 R1 =R2 时 ,b位质子表现为强度相等、对称的两组峰 ;当 R1 ≠ R2 时 ,b位质子不再表现为对称相等的两组峰 .2 )化合物 1(R1=R2 =CH3) ,在 - 6 0℃时 ,两个甲基碳仍表现为相同的化学位移 ,说明取代哌嗪比取代环己烷的环翻转能量低 .3) b位碳和羰基碳的化学位移基本不受 R1和 R2变化的影响 ,说明苯甲酰基与哌嗪环的空间构型不受 R1和 R2变化的影响 ,而 R1和 R2的改变对 a位碳的化学位移有一定影响
The 1 H and 1 3C NMR spectra of seven kinds of 1-benzoyl-4,4-dialkylpiperazine were reported and all the peaks were assigned. The effects of 1 H NMR, 1 C NMR spectroscopy The results show that: 1) Under the influence of benzoyl and R1, R2, when R1 = R2, the b-site protons show two groups of peaks with equal intensity and symmetry; when R1 ≠ R2, Then show two symmetrical peaks.2) Compound 1 (R1 = R2 = CH3), at -60 ℃, the two methyl carbons still show the same chemical shift, indicating that the substituted piperazine is more efficient than substituted cyclohexane The energy of ring inversion of alkane is low.3) The chemical shifts of carbon at position b and carbonyl carbon are basically unaffected by the changes of R1 and R2, indicating that the spatial configuration of benzoyl and piperazine ring is not affected by the changes of R1 and R2, Changes in R1 and R2 have some effect on the chemical shift of carbon at a