Cesium carbonate → Methyl 2,6-diamino-3-[2-(tert-butyldimethylsilanyloxymethyl)furan-3-yl]benzoate

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 3-bromo-2,6-diaminobenzoate (Intermediate 25, 2.6 g), 2-(tert-butyldimethylsilanyloxymethyl)furan-3-boronic acid (Intermediate 37, 3.5 g), cesium carbonate (11.35 g), tri-tert-butylphosphonium tetrafluoroborate (0.334 g) and tris-(dibenzylideneacetone)dipalladium (0.529 g) in dioxane (72 mL) and water (18 mL) was degassed and purged with nitrogen then heated at 70° C. for 75 minutes. After cooling, ethyl acetate and water were added and the mixture was filtered through Celite. The filtrate was separated and the organic layer was washed with brine, dried (MgSO4) and filtered. The filtrate was evaporated to dryness and the residue was purified by chromatography on silica eluting with a mixture of ethyl acetate and cyclohexane with a gradient of 5-20% to give methyl 2,6-diamino-3-[2-(tert-butyldimethylsilanyloxymethyl)furan-3-yl]benzoate (2.39 g) as a viscous oil which was used without further characterization.

Provenance & Evidence