The condensation of 6-acetyl-7-hydroxy-1,2,3,4-tetrahydronaphthalene (I) with allyl bromide (A) using of K2CO3 in DMF gives 6-acetyl-7-allyloxy-1,2,3,4-tetrahydronaphthalene (II), which is isomerized to 5-allyl-7-acetyl-6-hydroxy-1,2,3,4-tetrahydronaphthalene (III) by warming at 200 °C.
The nitration of (V) with nitric acid in sulfuric acid gives ethyl 10-propyl-4-oxo-5-nitro-6,7,8,9-tetrahydro-4H-naphtho[2,3-b]pyran-2-carboxylate (VII), which is hydrogenated with H2 over Pd/C in ethanol-acetic acid to afford the corresponding amino derivative (VIII).