Abstract The debenzoylation of 2-[(amino)(benzoylamino) methylidene] cyclohexane-1, 3- diones (addition products of cyclohexane-1, 3-diones with benzoylcyanamide) affords the corresponding 2-diaminomethylidenecyclohexane-1, 3-diones. The latter act as N, N- dinucleophiles in reactions with diethyl malonate in the presence of MeONa to form 6- hydroxy-2-(2, 6-dioxocyclohexylidene)-1, 2-dihydropyrimidin-4 (3 H)-ones. This reaction ...