SUMMARY
2Facile syntheses of [ 5-2H] -, [
6-H] -uracil and [ 5-2H7-,[6-HI-cytosine were investigated. The catalytic reaction of uracil or cytosine with 2H2 gas in alkaline media gave rise to [6-HI-compounds almost exclusively. On the other hand, the reaction of 5-bromouracil or 5-bromocytosine with gave rise to a mixture of [5-H]-, 16-HI-and [5-2H,6-2H]-compounds depending on the experimental conditions. By controlling the temperature, the pressure of 2H2 gas and the amounts of catalyst, [5-HI-uracil and [5-HI-cytosine were obtained. The isotopic distribution in each product was measured by 'H NMR spectroscopy combined with an HPLC method.