A solution of 4-(3,6-dimethyl-4,10-dihydro-3H-2,3,4,9-tetraaza-benzo[f]azulene-9-carbonyl)-2-methyl-benzonitrile from Example E101.1 (1.42 g, 4.0 mmol) in methanol (50 ml) at 0° C. was treated with cobalt(II) chloride hexahydrate (1.90 g, 8.0 mmol). The mixture was stirred for 15 min at room temperature then sodium borohydride (1.51 g, 40.0 mmol) was added portionwise. The reaction mixture was stirred for 2 h then saturated NH4Cl was added. The mixture was stirred for 30 min then the solid was filtered off through Celite® filter agent and the filtrate concentrated in vacuo. The residue was re-dissolved in EtOAc and saturated NaHCO3. The layers were partitioned and the aqueous layer was extracted further with chloroform. Organics were combined, dried and concentrated in vacuo. The residue was purified by flash chromatography on silica gel through an isolute (eluant; 1% 35% ammonia:9% methanol:90% dichloro-methane) to yield the title compound (511 mg, 35%).
