Potassium Carbonate → Methyl (4-((1E,4S)-4-((tert-butoxycarbonyl)amino)-3-oxohepta-1,6-dien-1-yl)-3-nitrophenyl)carbamate

Participants

Reaction Steps

To a vigorously stirred solution of 5E (4.47 g, 13.92 mmol) and 5D (2.6 g, 11.60 mmol) in THF (anhydrous) (115 mL) and EtOH (absolute) (1.148 mL) under nitrogen was added portion wise K2CO3 (anhydrous) (2.56 g, 18.56 mmol) at 0° C. The reaction mixture was allowed to raise to rt and then the mixture was heated at 55° C. The reaction mixture was then filtered with the aid of EtOAc and the filtrate evaporated to a residue which was dissolved in a small amount of methylene chloride and purified by normal phase chromatography to give 5F (4.38 g, 90%) as yellow solid. MS (ESI) m/z: 420.2 (M+H)+. 1H NMR (400 MHz, DMSO-d6) δ 10.36 (s, 1H), 8.22 (d, J=2.2 Hz, 1H), 7.89 (d, J=8.8 Hz, 1H), 7.83-7.73 (m, 2H), 7.21 (d, J=7.7 Hz, 1H), 7.02 (d, J=15.9 Hz, 1H), 5.77 (ddt, J=17.0, 10.2, 6.7 Hz, 1H), 5.16-5.01 (m, 2H), 4.32 (td, J=8.5, 4.9 Hz, 1H), 3.71 (s, 3H), 2.34-2.23 (m, 1H), 1.36 (s, 9H) ppm.

Provenance & Evidence