Condensation of 2-naphthylamine or N-benzyl-2-naphthylamines with formaldehyde and methyl 2,2-dimethyl-4,6-dioxocyclohexane-3-carboxylate

Condensation of 2-naphthylamine with formaldehyde and methyl 2,2-dimethyl-4,6-dioxocyclohexanecarboxylate afforded depending on the reaction conditions methyl 9,9-dimethyl-11-oxo-8,9,10,12-tetrahydro-7H-benzoa]acridine-10-carboxylate or 4-alkoxymethyl-1,4-dihydro-2??,6??-dioxo-4??,4??-dimethyl-2??H,3H,6??Hspirobenzof]quinoline-2,1??-cyclohexyl-3??-carboxylate. The condensation of N-benzyl-2-naphthylamines with formaldehyde and methyl 2,2-dimethyl-4,6-dioxocyclohexanecarboxylate provided with the quantitative yield the corresponding methyl 4-benzyl-1,4-dihydro-2??,6??-dioxo-4??,4??-dimethyl-2??H,3H,6??H-spirobenzof]quinoline-2,1??-cyclohexyl-3??-carboxylates.