Ammonia → 1-Methyl-1,4,5,10-tetrahydrobenzo[b]pyrazolo[3,4-e][1,4]diazepine

Participants

Reaction Steps

To a suspension of 3-methyl-4,9-dihydro-3H-2,3,4,9-tetraaza-benzo[f]azulen-10-one from Example E11.3 (3.01 g, 14.1 mmol) in anhydrous THF (100 ml) at 0° C. was added lithium aluminium hydride (2.13 g, 56.2 mmol), and the resulting suspension was heated at reflux for 18 h, then allowed to cool to room temperature. The mixture was cooled to 0° C., 35% ammonia solution (10 ml) was added dropwise over 15 min and the mixture was stirred at room temperature for 30 min. The resulting suspension was filtered through Celite® filter agent and the filtrate concentrated in vacuo. The residue was purified by flash chromatography on silica gel (eluant; 2% methanol:chloroform rising to 5% methanol:chloroform) to yield the title compound (1.60 g, 57%).

Provenance & Evidence