Abstract:
Homemade urea-
13C,
15N
2 was used to react with 3-methyl acrylonitrile closure to form cytosine-
13C,
15N
2 (2),which was protected by trimethylsilylation with BSA and condensed with 2-deoxy-2,2-difluoro-D-erythro-pentofuranose-3,5-dibenzoate-1-methanesulfonate at 120 ℃ to afford blocked gemcitabine-
13C,
15N
2. Hydrolytic removal of the blocking groups of gemcitabine-
13C,
15N
2 with NaOH gave gemcitabine-
13C,
15N
2, and its metabolite was obtained by further hydrolytic deamination of gemcitabine-
13C,
15N
2. The final products were characterized and detected by HPLC, LC-MS and NMR, and confirmed that the chemical purities were higher than 98%, isotopic abundances were 99%
13C, 98%
15N, and they were suitable for drug metabolism studies.