Tris(trimethylsilyl) phosphite → 5-Amino-2-(4-methoxy-2-methylphenethyl)benzo[f][1,7]naphthyridine-8-carbonylphosphonic acid

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension 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 toluene (0.27 M) was added tris(trimethylsilyl) phosphite (1.0 equiv.). The reaction was stirred at 80° C. for 60 minutes, then solvents were removed, and the resulting residue was taken up in DMSO (0.27 M), and IBX (1.5 equiv.) was added. The reaction was stirred at room temperature for 2.5 hour, and was filtered and directly purified on RP-HPLC using a C18 column, eluting with 10-40% 95:5 (MeCN/5 mM NH4OAc) in 10 mM NH4OAc (pH 9) gradient. The fractions containing the product were combined and concentrated in vacuo to give 5-amino-2-(4-methoxy-2-methylphenethyl)benzo[f][1,7]naphthyridine-8-carbonylphosphonic acid (14) as a solid. 1H NMR (Dimethylsulfoxide-d6): δ 9.84 (s, 1H), 9.35 (s, 1H), 9.09 (s, 1 H), 8.89 (s, 1 H), 8.76 (d, 1H, J=8.4 Hz), 8.60 (s, 1H), 8.19 (d, 1H, J=8.8 Hz), 7.04 (d, J=8.8 Hz, 1H), 6.70 (d, 1H, J=2.8 Hz), 6.62 (dd, 1H, J=2.8, 8.4 Hz), 3.64 (s, 3H), 3.15-3.09 (m, 2H), 2.97-2.91 (m, 2H), 2.23 (s, 3H). LRMS [M+H]=452.1

Provenance & Evidence