Water → HCID 86727345, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of ethyl 2-(6-hydroxy-3-oxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propionic acid ethyl ester (1.08 g, 4.07 mmol), 3-methanesulfonyloxy-azetidine-1-carboxylic acid tert-butyl ester (1.12 g, 4.48 mmol) and Cs2CO3 (2.65 g, 8.12 mmol) in DMF (20 mL) was stirred at 90° C. for 3 h. The reaction mixture was cooled to ambient temperature and poured into water (150 mL). The aqueous mixture was extracted with EtOAc (3×20 mL) and the combined organic phase was washed with brine (50 mL), dried over anhydrous Na2SO4, filtered and evaporated in vacuo. The residue was purified by column chromatography on silica gel (eluting with 10% EtOAc in petroleum ether) to give 3-[4-(1-ethoxycarbonyl-ethyl)-3-oxo-3,4-dihydro-2H-benzo[1,4]oxazin-6-yloxy]-azetidine-1-carboxylic acid tert-butyl ester as a white solid (0.7 g, 41%). 1H NMR (CDCl3, 400 MHz): δ 6.94 (d, J=8.4 Hz, 1H), 6.30 (m, 2H), 5.30 (q, J=7.2 Hz, 1H), 4.78 (m, 1H), 4.59 (d, J=15.2 Hz, 2H), 4.27 (m, 4H), 3.95 (m, 2H), 1.62 (d, J=7.2 Hz, 3H), 1.45 (s, 9H), 1.21 (t, J=7.2 Hz, 3H).

Provenance & Evidence