Hydrazine hydrate (1:1) → 6-Amino-7-fluoro-4-methyl-2,10-dihydro-9-oxa-1,2,4a-triaza-phenanthren-3-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-(6-amino-7-fluoro-3-thioxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propionic acid ethyl ester (0.400 g, 1.34 mmol) in EtOH (15 mL) was added hydrazine hydrate (98%, 0.430 g, 13.4 mmol) and the reaction mixture was stirred at 90° C. for 2 h. The reaction mixture was cooled to ambient temperature then concentrated in vacuo and the residue was purified by column on silica gel (basified by treatment with triethyl amine, eluting with 10-20% MeOH in DCM) to give 6-amino-7-fluoro-4-methyl-2,10-dihydro-9-oxa-1,2,4a-triaza-phenanthren-3-one as a light yellow solid (0.316 g, 94%). 1H NMR (DMSO-d6, 400 MHz): δ 10.73 (s, 1H), 6.78 (d, J=11.6 Hz, 1H), 6.62 (d, J=8.8 Hz 1H), 4.84 (brs, 2H), 4.44-4.53 (m, 3H), 1.29 (d, J=6.8 Hz, 3H).

Provenance & Evidence