Water → tert-Butyl 2-(6-formylpyridin-2-yl)benzyl(phenyl)carbamate

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Reaction Conditions

Reaction Steps

A mixture of water (160 mL) and methanol (40 mL) was combined with sodium carbonate (3.80 g, 35.9 mmol), and the mixture was sparged with nitrogen for 30 min. In a separate flask were combined, under nitrogen, 6-bromo-2-pyridinecarboxaldehyde (2.67 g, 14.4 mmol), tert-butyl phenyl(2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl)carbamate (5.87 g, 14.4 mmol), tetrakis(triphenylphosphinio)palladium (0.829 g, 0.718 mmol), and toluene (150 mL). The water-methanol solution was added via cannula to the toluene solution, and the biphasic mixture was heated to 80° C. overnight. At this time 1H NMR spectroscopic analysis of an aliquot indicated that the reaction was complete. The clear yellow organic layer was separated, dried with brine, then over magnesium sulfate. The crude product was purified by chromatography on silica using 1:1 hexanes:dichloromethane elutant and increasing the strength by addition of up to 10% EtOAc. The product was isolated as a sticky oil (4.7 g, 840%). 1H NMR (CD2Cl2, 500 MHz): 10.0 (s, 1H), 7.83-7.92 (m, 2H), 7.56 (d, 1H), 7.50 (d, 1H), 7.44 (m, 1H), 7.36 (m, 2H), 7.17 (t, 2H), 7.01 (t, 1H), 7.0 (br d, 2H), 5.11 (s, 2H), 1.34 (s, 9H).

Provenance & Evidence