Hydrochloric Acid → Olanzapine

Participants

Reaction Conditions

Reaction Steps

A suspension of 2,4-bis(4-methyl-1-piperazinyl)-3-propylidene-3H-[1,5]benzodiazepine (11.90 g, 31.3 mmol), sulphur (20.07 g, 626 mmol) and triethyl amine (4.34 ml, 31.3 mmol) in dimethyl sulfoxide (100 ml) and 1-propanol (100 ml) was heated at 100° C. for five days. The resulting black suspension was cooled and filtered off and the filtrate was evaporated at reduced pressure to obtain a viscous black oil. Dichloromethane (600 ml) and HCl (0.2 M, 600 ml) were added and the phases were separated. The organic phase was extracted again with HCl (0.5 M, 100 ml). The combined water phases were made alkalic at a pH of 9 to 10. Dark brown precipitate was filtered off. Dichloromethane (250 ml) was added to the filtrate. The phases were separated and the water phase was extracted with dichloromethane (2×60 ml). The organic phase was dried over anhydrous Na2SO4 and the solvent was evaporated at reduced pressure. The black oil was combined with precipitate and purified by chromatography on silica gel, eluted with ethyl acetate/triethylamine 50/1 to obtain 1.195 g (12%) of the title product.

Provenance & Evidence