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

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%).

1. temperaturethe resulting suspension was heated
2. temperatureat reflux for 18 h
3. temperatureThe mixture was cooled to 0° C.
4. filtrationThe resulting suspension was filtered through Celite®
5. filtrationfilter agent
6. concentrationthe filtrate concentrated in vacuo
7. customThe residue was purified by flash chromatography on silica gel (eluant; 2% methanol:chloroform rising to 5% methanol:chloroform)

ORD record

ord-8c7f913d13204c818495cc604c6a07d6

Source dataset

uspto-grants-2012_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08202858B2