合成路线1

The synthetic procedure was carried out according to Cholody et al. (1). The starting 1-chloro-7-hydroxy-4-nitro-9(10H)-acridinone (I) was synthesized by the method of Capps (2). The condensation of (I) with 2-(diethylamino)ethylamine (II) in DMF gave 1-[2-(diethyl-amino)ethylamino]-7-hydroxy-4-nitro-9(10H)-acridinone (III) in good yield and purity. The reduction of the nitro group of (III) with hydrazine hydrate and Raney Ni in THF yielded the amino intermediate (IV), extremely unstable due to its sensitivity to oxidation, which was immediately used in the next step as crude hydrochloride salt. The salt (IV) was refluxed with 95% formic acid giving the imidazoacridinone derivative. The final product was isolated directly from the reaction mixture as hydrochloride salt after acidification with concentrated HCl and recrystalized from a mixture of methanol/acetone.