Ethyl Acetate → Ethyl [3-(bromomethyl)-1H-pyrazolo[3,4-b]pyridin-1-yl]acetate
Reaction equation
C(OCC[N:7]1[C:11]2=[N:12][CH:13]=[CH:14][CH:15]=[C:10]2[C:9]([CH3:16])=[N:8]1)(=O)C.C1C(=O)N([Br:24])C(=O)C1.[CH3:25][CH2:26][O:27][C:28]([CH3:30])=[O:29]>C(Cl)(Cl)(Cl)Cl.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1>[CH2:26]([O:27][C:28](=[O:29])[CH2:30][N:7]1[C:11]2=[N:12][CH:13]=[CH:14][CH:15]=[C:10]2[C:9]([CH2:16][Br:24])=[N:8]1)[CH3:25]Participants
Procedure
A mixture of (3-methyl-pyrazolo[3,4-b]pyridine-1-yl)ethyl acetate (2.5 mmol, 1 eq.), NBS (3.0 mmol, 1.2 eq.), and benzoyl peroxide (0.05 mmol, 0.02 eq.) in 10 mL of CCl4 was refluxed for 1.5 h. The resultant mixture was cooled to rt, and diluted with 500 mL of EtOAc. The resultant solution was then washed with 100 mL of sat. sodium bicarbonate aqueous solution, brine solution, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The crude residue was purified by silica gel chromatography (20% EtOAc in hexane to 35% EtOAc in hexane) to provide 450.2 mg of the desired product: HPLC retention time=2.50 minutes (Agilent Zorbax SB-C18, 2.1×50 mm, 5μ, 35° C.) using 1 ml/min flow rate, a 2.5 minute gradient of 0% to 100% B with a 1.1 minute wash at 100% B (A=0.1% formic acid/5% acetonitrile/94.9% water, B=0.1% formic acid/5% water/94.9% acetonitrile); MS (ES) M+H expect=298.0. found=298.3.
Workup
- temperaturewas refluxed for 1.5 h
- washThe resultant solution was then washed with 100 mL of sat. sodium bicarbonate aqueous solution, brine solution
- dry with materialdried over anhydrous sodium sulfate
- filtrationfiltered
- concentrationconcentrated in vacuo
- customThe crude residue was purified by silica gel chromatography (20% EtOAc in hexane to 35% EtOAc in hexane)
Sources & evidence
- ORD record
- ord-e63616dabe2548b7a083ef02ce44932d
- Source dataset
- uspto-grants-2013_02
- Patent number
- US08383630B2
Reaction notes
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