Lawesson's reagent → HCID 86727358, compound

Participants

Reaction Steps

To a solution of 3-[4-(1-ethoxycarbonyl-ethyl)-3-oxo-3,4-dihydro-2H-benzo[1,4]oxazin-6-yloxy]-3-methyl-azetidine-1-carboxylic acid tert-butyl ester (0.250 g, 0.575 mmol) in toluene (5 mL) and DME (5 mL) was added Lawesson reagent (0.372 g, 0.920 mmol) and the mixture was heated to reflux for 4 h. The mixture was cooled to ambient temperature and concentrated in vacuo. The residue was purified by column chromatography on silica gel (eluting with 5% to 10% EtOAc in petroleum ether) to give 3-[4-(1-ethoxycarbonyl-ethyl)-3-thioxo-3,4-dihydro-2H-benzo[1,4]oxazin-6-yloxy]-3-methyl-azetidine-1-carboxylic acid tert-butyl ester (0.095 g, 36.6%) as a pale yellow solid. 1H NMR (CDCl3, 400 MHz): δ 6.90 (d, J=8.8 Hz, 1H), 6.67 (brs, 1H), 6.38 (m, 1H), 6.31 (s, 1H), 4.85 (d, J=15.2 Hz, 2H), 4.14 (m, 4H), 3.87 (m, 2H), 1.64 (d, J=7.2 Hz, 3H), 1.59 (s, 3H), 1.42 (s, 9H), 1.13 (t, J=7.2 Hz, 3H).

Provenance & Evidence