Calcium Carbonate → HCID 178454989, compound

Participants

Reaction Steps

[4-[tert-butyl(dimethyl)silyl]-3,5,6-trifluoro-2-pyridyl]-(2-fluoro-3-pyridyl)methanone (159 g, 429.2 mmol) was dissolved in dioxane (1.6 L) and calcium carbonate (85.91 g, 858.4 mmol) was added. The reaction was in an ice bath and hydrazine hydrate (107.4 g, 104.4 mL, 2.146 mol) was added dropwise over 30 minutes. The resultant mixture was stirred overnight, after which time the thick suspension became a heterogeneous red solution. The reaction mixture was filtered through a pad of Celite, washing copiously with EtOAc/MeOH 7:1 (2×500 mL) and a small amount of water (100 mL). The filtrate was partitioned between EtOAc (1 L) and water (500 ml). The organic phase was washed with a sat aq NaHCO3 (500 mL). The combined aqueous layers were back-extracted with EtOAc (2×200 ml) and the combined organics were washed with brine (400 ml), dried over MgSO4 and filtered and concentrated to an orange solid. The solid was triturated with dichloromethane and filtered, washing with dichloromethane and petrol. This gave the title compound as an off-white solid (103.8 g). The filtrate was concentrated under reduced pressure. The resulting solid was again triturated and filtered, washing with more petrol to give an off-white solid (36.7 g). The title compound was obtained as an off-white solid (total weight 140.5 g, 90%); 1H NMR (CDCl3) 0.55 (6H, s), 1.02 (9H, s), 7.21 (1H, m), 8.69 (1H, m), 8.91 (1H, s), 11.69 (1H, brs); MS ES (+) 365.18 (M+1).

Provenance & Evidence