Dyn amic NM R of Ranit idine: An Empirica l and Co mputational Study

In this work we h ve studied conformation of ranitidine by dy namic nuclear magnetic resonance spectroscopy (DN MR) in f our different solvents: chloroform, acetone, dimethylsulfoxide, a nd deuteriumoxide. Ra nitidine ha s three tatu meric forms of enamine, nitoic acid, and imi ne, but its stable struct ure is enami ne. Temperature dependent ۱HNMR spectra of ranitidine which achieved at ۵۰ ۰MHz wer e consistent with the following fr ee activation of energies ΔG# (kcal mol-۱): chloroform = ۱۶.۲; acetone = ۱۵.۴; dim ethylsulfoxi de = ۱۵.۱. The experi mental resu lts were confirmed by DFT theoretical calculations at t he B۳LYP/ ۶-۳۱۱++G (d, p) level of theory. It was also proved that ranitidine has the form of imine in deuteriumoxide, whil e in the three other solvents, acetone, chloroform, an d dimethylsulfoxide, has the enamine form

کلیدواژه ها:

Ranitidine ، DNMR ، G aussian ، D FT