Hydrochloric Acid → (R)-tert-butyl 3-(6-(5-(2-chloro-6-fluorophenyl)-1H-indol-3-yl)pyrazin-2-yloxy)piperidine-1-carboxylate

Participants

Reaction Steps

To a slurry of NaH 60% in mineral oil (0.047 g, 1.171 mmol) in 2 mL DMF at 0° C. was added (R)-tert-butyl 3-hydroxypiperidine-1-carboxylate (0.236 g, 1.171 mmol). The reaction was warmed to RT. After 10 min, solid 5-(2-chloro-6-fluorophenyl)-3-(6-chloropyrazin-2-yl)-1-tosyl-1H-indole (0.200 g, 0.390 mmol) was added and the reaction became dark brown. After 30 min, the reaction was sealed and heated to 80° C. overnight. Additional NaH 60% in mineral oil (0.047 g, 1.171 mmol) and (R)-tert-butyl 3-hydroxypiperidine-1-carboxylate (0.236 g, 1.171 mmol) were added, the reaction was sealed, and heated to 120° C. for 1 h. The reaction was cooled and treated with ice, water, and EtOAc, and the aqueous layer was acidified with 1N aqueous HCl. The aqeuous layer was extracted 2×EtOAc, and the combined organics were washed 1× water, 1× brine, dried over Na2SO4, filtered, and concentrated in vacuo. The material was treated with DCM and purified by silica gel chromatography (40 g column) using 0-60% EtOAc/hexane. The product-containing fractions were concentrated to afford (R)-tert-butyl 3-(6-(5-(2-chloro-6-fluorophenyl)-1H-indol-3-yl)pyrazin-2-yloxy)piperidine-1-carboxylate (0.077 g, 0.147 mmol, 37.7% yield) as a light-yellow oil. MS (ESI, pos. ion) m/z: 523 (M+1).

Provenance & Evidence