Tetraethyl methylenediphosphonate → (E)-diethyl 2-(5-amino-2-(4-methoxy-2-methylphenethyl)benzo[f][1,7]naphthyridin-8-yl)vinylphosphonate

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of NaH (1.2 equiv.) in THF (0.1 M) cooled at 0° C. was added a solution of tetraethyl methylenediphosphonate (1.3 equiv.) in THF (0.21 M). To the resulting reaction mixture was added a solution of 5-amino-2-(4-methoxy-2-methylphenethyl)benzo[f][1,7]naphthyridine-8-carbaldehyde (2-2) (Example 9—Step 1) (1.0 equiv.) in THF (0.08 M). The reaction was stirred at room temperature for 30 minutes, then solvents were removed in vacuo, and the resulting residue was purified by a COMBIFLASH® system (ISCO) using a gradient of 0-5% MeOH/DCM to provide (E)-diethyl 2-(5-amino-2-(4-methoxy-2-methylphenethyl)benzo[f][1,7]naphthyridin-8-yl)vinylphosphonate (3-1) as a colorless solid.

Provenance & Evidence