The reaction of 2-methoxy-9-methylcarbazole-3-carbaldehyde (I) with malonic acid gives the propenoic acid (III), which by treatment with sodium azide and ethyl chloroformate is converted into the azide (IV). The cyclization of (IV) in refluxing ortho-dichlorobenzene affords 5-methoxy-7-methyl-2,7-dihydro-1H-pyrido [4,3-c]carbazol-1-one (V), which by treatment with POCl3 is converted into the 1-chloro derivative (VI). Finally, this compound is dechlorinated by hydrogenation with H2 over Pd/C.