tert-Butyl acrylate → tert-butyl (E)-3-(7-oxo-5,6,7,8-tetrahydro-1,8-naphthyridin-3-yl)acrylate

Beteiligte Stoffe

Reaktionsschritte

A solution of 6-bromo-3,4-dihydro-1H-1,8-naphthyridin-2-one (12.99 g, 57 mmole), tert-butyl acrylate (34 mL, 232 mmole), DIEA (21.2 mL, 122 mmole), Pd(OAc)2 (1.3 g, 5.8 mmole) and P(o-tol)3 (3.5 g, 11.5 mmole) in propionitrile (200 mL) and DMF (50 mL) was purged with Ar, then was heated at reflux. After 18 h the reaction was allowed to cool to room temperature and was concentrated to dryness. The residue was purified by flash chromatography on silica gel (2-4% MeOH/CHCl3). The resulting residue was triturated with 1:1 Et2O/petroleum ether, collected, and dried, and the resulting material was triturated with 1:1 MeOH/H2O, collected, and dried, to give the title compound (7.09 g, 45%) as an off-white solid: 1H NMR (400 MHz, d6-DMSO) δ 10.70 (s, 1 H), 8.35 (d, J=2.0 Hz, 1H), 8.04 (s, 1 H), 7.50 (d, J=16.0 Hz, 1 H), 6.51 (d, J=16.0 Hz, 1 H), 2.89 (t, 2H), 2.53 (t, 2 H), 1.48 (s, 9H); MS (ES) m/e 275.2 (M+H)+.

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