Lithium Hydroxide → 2-[(3S)-7-chloro-4-(3-oxo-4H-1,4-benzoxazine-6-carbonyl)-2,3-dihydro-1,4-benzoxazin-3-yl]acetic acid

Participants

Reaction Steps

LiOH (1.40 g, 58.3 mmol) was dissolved in water (50 mL) and added to (S)-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 21a, 5.71 g, 11.7 mmol) in THF (50 mL). The reaction mixture was stirred at rt for 75 min EtOAc (150 mL) was added. Washed with HCl (1 M, 100+50 mL) and brine (50 mL). The organic phase was dried over Na2SO4 and after filtration the solvents were evaporated in vacuo to yield the crude the title compound (82 mg, 107%) which was used further in the synthesis of Example 5a.

Provenance & Evidence