Hydrochloric Acid → 1-(5-(5-(2,6-difluorophenyl)-1H-pyrrolo[3,2-b]pyridin-3-yl)pyridin-3-yl)piperidin-4-amine

Participants

Reaction Conditions

Reaction Steps

A solution of tert-butyl 1-(5-(5-(2,6-difluorophenyl)-1-tosyl-1H-pyrrolo[3,2-b]pyridin-3-yl)pyridin-3-yl)piperidin-4-ylcarbamate (79 mg, 0.120 mmol, 88% pure) in THF (2 mL) was treated with NaOH 5M (0.048 mL, 0.239 mmol). The reaction mixture was heated to reflux (bath temperature 80° C.). After 1 h, NaOH 5M (0.45 mL, 0.96 mmol, 8.0 equiv) was further added. After 23 h, the solution was cooled to 23° C., concentrated in vacuo and purified by silica gel chromatography (eluent: 1-7% MeOH/DCM), affording tert-butyl 1-(5-(5-(2,6-difluorophenyl)-1H-pyrrolo[3,2-b]pyridin-3-yl)pyridin-3-yl)piperidin-4-ylcarbamate (31 mg, 51%). MS (ESI, pos. ion) m/z: 506.2 (M+1). A solution of tert-butyl 1-(5-(5-(2,6-difluorophenyl)-1H-pyrrolo[3,2-b]pyridin-3-yl)pyridin-3-yl)piperidin-4-ylcarbamate (31 mg, 0.061 mmol) in MeOH (0.5 mL) was treated with HCl, 5-6n in IPA (0.123 mL, 0.613 mmol). The reaction was heated to 50° C. under N2. After 2 h, the reaction was cooled to 23° C. and the product (as HCl salt) was free-based using a Silicycle Si-propylsulfonic acid ion exchange column (catalog # R51230B). The compound was slurried in MeOH/DCM and added to a pad of the resin (wetted and flushed with 10 mL MeOH). It was flushed with MeOH (50 mL), and then the product was “released” using 2.0 M NH3 in MeOH solution (50 ml). The final filtrate was concentrated, affording 1-(5-(5-(2,6-difluorophenyl)-1H-pyrrolo[3,2-b]pyridin-3-yl)pyridin-3-yl)piperidin-4-amine MS (ESI, pos. ion) m/z: 406.3 (M+1).

Provenance & Evidence