Among various C(5)-, N(1)-, and N(3)-substituted uracils, 1-substituted 5-n
itrouracil derivatives were reduced by an NADH model, l-benzyl 1,4-dihydron
icotinamide, to give 5, 6-dihydro-5-nitrouracil derivatives, the formation
of which was accelerated to a large extent by the use of Mg2+ as a catalyst
.