Nitrogen → Onalespib

Participants

Reaction Steps

The product from Step 11 (0.9 Kg, 1.53 mol) was dissolved in isopropanol (6.8 L) and water (1.04 L) and after purging with N2 10% Pd/C (90 g) and K2CO3 (0.212 Kg, 1.53 mol) were added and the suspension was hydrogenated for 60 to 70 mins under an 3 Barr pressure of H2. The solution was diluted with water (0.5 L) and filtered. To the filtrate was added aqueous HCl (30% hydrochloric acid, 0.85 Kg diluted with water 5.42 Kg) and the solution was concentrated at 60° C. under vacuum (removing 10 L isopropanol). Water (0.45 L) was added to the solution and concentration continued (until a further 10 L isopropanol had been removed). The aqueous phase was washed with EtOAc (4.61 L), diluted with acetonitrile (4.06 L) and netralised to pH 7.5-8.5 by addition of conc ammonia solution (0.35 Kg). The suspension was stirred for 2.5 h and then the solid was removed by filtration. The residue was washed with acetonitrile (2×0.8 L) and dried at 40° C. to constant weight to give the title compound 588 g (94% yield).

Provenance & Evidence