Water → HCID 58294639, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of sulfuric acid (98%, 6 kg), water (6 L), and methanol (6 L) is added to an autoclave charged with 6-methoxy-indeno[2,1-b]pyridin-9-one (1.2 kg) and wet 10% palladium on carbon (50%, 0.48 kg). The autoclave is purged with nitrogen and filled then with hydrogen (100 psi). The mixture is heated to 60° C. and maintained at this temperature and hydrogen pressure until the starting material is completely consumed (2-12 h). The mixture is cooled to 50-55° C. and filtered over Celite. The Celite is washed with a warm 1:1 mixture of water and methanol several times (total 20 L). The combined filtrate is added to an autoclave charged with wet 10% palladium on carbon (50%, 0.96 kg). The autoclave is purged with nitrogen and filled then with hydrogen (100 psi). The mixture is heated to 60° C. and maintained at this temperature and hydrogen pressure until the intermediate is completely consumed (12-24 h). The mixture is cooled to ambient temperature and filtered over Celite. The Celite is washed with a mixture of methanol and water (5 L/5 L). The combined filtrate is cooled to 0-10° C. and the pH value is adjusted to 10-11 using 30% aqueous NaOH solution while maintaining the solution temperature below 40° C. Water (10 L) is added and the resulting mixture is extracted with dichloromethane (2×5 L). The combined extract is washed with 10% aqueous NaCl solution and concentrated. The residue is taken up twice in methyl ethyl ketone and concentrated again to give the crude title compound.

Provenance & Evidence