“…[10] ple, ethacridine 1 was transformed into chloro compound 2 and this into the 2,2-dimethoxyethanamine 3, acid-catalysed closure of which produced (Scheme 1) a pyrido[4,3,2-kl]acridine 4. [10] Electrophilic substitution of 3 with 4-nitrophenyldiazonium fluoroborate allows later introduction of an amine function by reduction and thence by condensation with 1,10-phenanthroline-5,6-dione, formation of octacyclic analogue 5 of eilatin (Scheme 1) [9] (for structure of eilatin see Figure 4) Alkylpyrido[4,3,2-kl]acridines 7 were prepared [11,12] using the previously described synthetic procedure . [13] The synthesis starts with a cycloaddition of dimethylaminoprop-2-yne (or 5chloropent-1-yne) to 9-azidoacridine to give a regioisomeric mixture of triazolylacridines 6a and 6b (or 6c and 6d) (Scheme 2).…”