[IR and Raman spectroscopic studies on the derivatives of butylphthalide]

dl-NBP is a potentially beneficial and promising drug for treatment of ischemic stroke with multiple actions that affect different pathophysiologic processes, such as improving microcirculation, decreasing brain infarct volume, regulating energy metabolism, and especially inhibiting platelet aggregation and reducing thrombus formation. However, NBP is limited to use in the clinic by other side effects, such as elevated aminotransferase, abnormal liver function and digestive response. Some derivates of NBP were synthesized with the halides (F, Cl and Br) on the 6-position, and their IR and Raman spectra were measured. They proved the complemental information for deducing their structure. By comparing the spectra of the NBP, the band of disubstituted benzene disappeared in the derivatives, and the band of trisubstituted benzenes were observed. The stretching vibrational band of C--H was detected in the Raman spectra, but was not observed in IR. In the low frequency region, the deformation vibration band of --C--C--C--C was also observed in the Raman spectra.