Azobisisobutyronitrile → tert-Butyl 5-bromo-3-(bromomethyl)-1H-pyrazolo[3,4-b]pyridine-1-carboxylate

HRID 1924295Notes

Reaction equation

[Br:1][C:2]1[CH:3]=[C:4]2[C:10]([CH3:11])=[N:9][N:8]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[C:5]2=[N:6][CH:7]=1.[Br:19]N1C(=O)CCC1=O.N(C(C)(C)C#N)=NC(C)(C)C#N>C(Cl)(Cl)(Cl)Cl>[Br:1][C:2]1[CH:3]=[C:4]2[C:10]([CH2:11][Br:19])=[N:9][N:8]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[C:5]2=[N:6][CH:7]=1

Participants

Conditions

Temperature: 80 °C

Procedure

A mixture of tert-butyl 5-bromo-3-methyl-1H-pyrazolo[3,4-b]pyridine-1-carboxylate x154 (10.8 mmol, 1 eq, 3.37 g), N-bromosuccinimide (1.92 g, 1 eq, 10.8 mmol) and azo-bisiso-butyronitrile (AIBN) (10.8 mmol, 1 eq, 1.77 g) in CCl4 (50 ml) is heated for 2 hours at 80° C. The solvent is removed under reduce pressure, water is added and the resulting mixture is extracted with dichloromethane. The combined organic phases are dried over MgSO4, filtered and volatiles removed under reduced pressure. The product is purified by chromatography on silicagel (hexane/AcOEt 8/2) and recristallized in AcOEt to afford 0.28 g of pure tert-butyl 5-bromo-3-(bromomethyl)-1H-pyrazolo[3,4-b]pyridine-1-carboxylate x155.

Workup

customThe solvent is removed
additionis added
extractionthe resulting mixture is extracted with dichloromethane
dry with materialThe combined organic phases are dried over MgSO4
filtrationfiltered
customvolatiles removed under reduced pressure
customThe product is purified by chromatography on silicagel (hexane/AcOEt 8/2)

Sources & evidence

ORD record: ord-300bccfef92f42f6b2c7f32190f415a6
Source dataset: uspto-grants-2012_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08178533B2

Reaction notes

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