2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 8-Chloro-2-methyl-6-phenyl-4H-pyrazolo[1,5-a][1,4]benzodiazepine

Participants

Reaction Steps

A solution of 2.52 g. (7.8 mmol) of the end product of Example 16 in 75 ml. dry THF was reduced with 3.12 ml. (31.2 mmol) of BMS according to the procedure described above in 6, Method B. The crude product from this reduction was then treated with 2.15 g. (9.4 mmol) of DDQ according to the oxidation procedure described above in Example 8. The crude oxidation product was chromatographed on a 29×20 cm column of silica gel packed in benzene and eluted first with 3% EtOAc in benzene and then 5% EtOAc in benzene. Recrystallization from CH3OH/H2O of the material isolated from the column yielded the analytically pure end product as colorless needles: mp 105°-107°.

Provenance & Evidence