Hydrochloric Acid → 2-(7-chloro-4-(3-oxo-3,4-dihydro-2H-benzo[b][1,4]oxazine-6-carbonyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-3-yl)acetic acid

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Reaction Steps

A mixture of ethyl {7-chloro-4-[(3-oxo-3,4-dihydro-2H-1,4-benzoxazin-6-yl)carbonyl]-3,4-dihydro-2H-1,4-benzoxazin-3-yl}acetate (Intermediate 21, 42 mg, 0.10 mmol) and LiOH (1 M, 0.146 mL, 0.15 mmol) in THF (2 mL) was stirred at rt for 2 h. Additional LiOH (1 M, 0.070 mL, 0.07 mmol) was added and the mixture was stirred for 2 h. HCl (1 M, 5 mL) was added and the aq. phase was extracted with DCM (3×5 mL). The combined organic layers were dried by passage through a phase separator and concentrated in vacuo providing the title compound (38.0 mg, 97%) as a white solid.

Provenance & Evidence