N,N-Dimethylethylenediamine → 2-methyl-5-[[2-(dimethylamino)ethyl]amino]isoquino[8,7,6-cd]indazole-6(2H)-one

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Reaction Steps

A 1M solution of N,N-dimethylethylenediamine in pyridine (0.10 mL) is added to a stirred suspension of 2-methyl-5-(p-toluenesulfonyloxy)isoquino[8,7,6-cd]indazole-6(2H)-one (0.02 g) in dry pyridine (2 mL). After stirring at room temperature for one hour the reaction mixture is heated at 70° C. for 13 hours while additional amounts of N,N-dimethylethylenediamine solution (0.1; 0.05; 0.05 mL) are added after 2, 4 and 11 hours respectively. Pyridine and excess N,N-dimethylethylenediamine are removed by distillation at reduced pressure and the obtained residue is partitioned between CH2Cl2 (50 mL) and brine (10 mL) to which NaHCO3 saturated solution is added (1 mL). The organic solution is dried over anhydrous Na2SO4 and the solvent removed by distillation. The orange residue obtained is purified by silica-gel column chromatography (eluant: CHCl3 /MeOH 95/5 (30 mL) followed by CHCl3 /MeOH/NH4OH 90/15/0.5 (50 mL) to give 2-methyl-5-[[2-(dimethylamino)ethyl]amino]isoquino[8,7,6-cd]indazole-6(2H)-one (0.011 g) as a reddish orange solid.

Provenance & Evidence