抄録
2-Substituted 2, 6-dihydro-3-hydroxy-7H-pyrazolo [4, 3-d] pyrimidin-7-ones bearing a methyl, phenyl, p-tolyl, m-tolyl or p-chlorophenyl group at the 2-position were synthesized by the reduction of ethyl 4-nitroso-5-hydroxy-1H-pyrazole-3-carboxylates and subsequent condensation of the resulting ethyl 4-amino-5-hydroxy-1H-pyrazole-3-carboxylates with formamide. Ethyl 4-nitroso-5-hydroxy-1H-pyrazole-3-carboxylates were prepared by nitrosation of ethyl 5-hydroxy-1H-pyrazole-3-carboxylates, which were derived from diethyl oxalacetate and monosubstituted hydrazines such as methyl-, phenyl-, p-tolyl-, m-tolyl-, and p-chlorophenylhydrazines.
