Bromotrimethylsilane → (E)-2-(5-amino-2-(4-methoxy-2-methylphenethyl)benzo[f][1,7]naphthyridin-8-yl)vinylphosphonic acid

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Reaction Steps

To a solution of (E)-diethyl 2-(5-amino-2-(4-methoxy-2-methylphenethyl)benzo[f][1,7]naphthyridin-8-yl)vinylphosphonate (3-1) (1.0 equiv.) in DCM (0.095 M) at 0° C. was added TMSBr (10 equiv.). The reaction was warmed to room temperature over 2 hours, and then quenched with small amounts of MeOH. The DCM was removed by evaporation, and then added DMSO/water. The mixture was adjusted to pH 9 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 the (E)-2-(5-amino-2-(4-methoxy-2-methylphenethyl)benzo[f][1,7]naphthyridin-8-yl)vinylphosphonic acid (10) as a solid. 1H NMR (Dimethylsulfoxide-d6): δ 9.76 (s, 1H), 9.33 (s, 1H), 9.03 (s, 1H), 8.82 (s, 1H), 8.60 (d, 1H, J=8.4 Hz), 7.87 (d, 1H, J=8.4 Hz), 7.78 (s, 1H), 7.31 (dd, 1H, J=17.6, 21.6 Hz), 7.03 (d, 1H, J=8.4 Hz), 6.69 (m, 2H), 6.61 (dd, 1H, J=2.8, 8.4 Hz), 3.64 (s, 3H), 3.14-3.06 (m, 2H), 2.97-2.91 (m, 2H), 2.23 (s, 3H). LRMS [M+H]=450.2

Provenance & Evidence