Potassium Phosphate, Tribasic → 2-((4-Ethoxyphenyl)ethynyl)-8-methylbenzo[f][1,7]naphthyridin-5-amine

Participants

Reaction Conditions

Reaction Steps

To a round bottom flask with refluxing condenser were added 3-chloro-5-((4-ethoxyphenyl)ethynyl)picolinonitrile (from the previous step) (1 eq.), tert-butyl 5-methyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenylcarbamate (from Example 5/Step 2) (1.25 eq.), K3PO4 (2 eq.), tris(dibenzylideneacetone)dipalladium(0) (0.05 eq.), and 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (0.1 eq.). n-Butanol and water (5:2, 0.2 M) were added, and the content were degassed (vacuum followed by nitrogen flush) for three times. The reaction mixture was stirred vigorously under nitrogen at 100° C. overnight in an oil bath. The content were cooled down and were taken up in 200 mL of water followed by extraction with methylene chloride. Combined organic layers were dried (Na2SO4) and concentrated. Flash chromatography (silica gel, 0-50% EtOAc in CH2Cl2) afforded the product 2-((4-ethoxyphenyl)ethynyl)-8-methylbenzo[f][1,7]naphthyridin-5-amine.

Provenance & Evidence