A suspension of 7-Bromo-4-[2-(4-methyl-piperazin-1-yl)-2-oxo-ethyl]-1,3,4,5-tetrahydro-pyrido[2,3-e][1,4]diazepin-2-one (1.39 g, 3.64 mmol) in propionitrile (32 mL) and DMF (8 mL) was de-oxygenated with Ar for 15 min. The mixture was treated with tert-butyl acrylate (2.1 mL, 14 mmol) and (i-Pr)2EtN (1.3 mL, 7.4 mmol) and then was de-oxygenated with Ar for 10 min. Pd(OAc)2 (83 mg, 0.37 mmol) and P(o-tol)3 (0.22 g, 0.73 mmol) were added simultaneously, and the mixture was de-oxygenated a third time for 10 min. The mixture was heated to reflux overnight, then allowed to cool. The resulting precipitate was isolated by filtration and dissolved in CH2Cl2. The solution was filtered through Celite and the solvent was removed in vacuo to give the title compound (1.13 g, 72%) as an off-white solid: MS (ESI) m/e 430 (M+H)+.
