Citric Acid → 6-(2,4-Difluoro-benzyl)-3,3-dimethyl-2,3-dihydro-pyrrolo[3,2-b]pyridine-1-carboxylic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

To a nitrogen-degassed mixture of 6-bromo-3,3-dimethyl-2,3-dihydro-pyrrolo[3,2-b]pyridine-1-carboxylic acid tert-butyl ester (4.90 g, 15.0 mmol), lithium bromide (3.87 g, 45.0 mmol), (1,3-diisopropylimidazol-2-ylidene)(3-chloropyridyl)palladium (II) dichloride (0.2 g, 0.3 mmol), 1-methyl-2-pyrrolidinone (40 mL) and THF (40 mL) was added a solution of 2,4-difluoro-benzylzinc bromide in THF (0.5 M, 60 mL, 30 mmol) and resulting mixture was stirred at 20° C. for 1 h. The mixture was poured into water (200 mL) and 5% aqueous citric acid (50 mL) and the resulting mixture extracted with Et2O (3×100 mL). The organic phase was washed with water (100 mL), brine (3×100 mL), dried (MgSO4) and evaporated in vacuo to give an oil. Chromatography (SiO2, eluted with petrol-EtOAc 0-30%) gave the title compound (5.7 g, 100%) as an oil. MS: [M+H]+=375.

Provenance & Evidence