Trifluoroacetic anhydride → 2-(6-Acetoxy-3-oxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propionic acid ethyl ester

HRID 518989Notes

Reaction equation

HRID 518989 reaction equation
NC(N)=O.OO.C([O-])(O)=O.[Na+].[CH2:12]([O:14][C:15](=[O:32])[CH:16]([N:18]1[C:23]2[CH:24]=[C:25](C(=O)C)[CH:26]=[CH:27][C:22]=2[O:21][CH2:20][C:19]1=[O:31])[CH3:17])[CH3:13].[C:33]([O:39]C(C(F)(F)F)=O)([C:35](F)(F)F)=[O:34]>C(Cl)Cl>[CH2:12]([O:14][C:15](=[O:32])[CH:16]([N:18]1[C:23]2[CH:24]=[C:25]([O:39][C:33](=[O:34])[CH3:35])[CH:26]=[CH:27][C:22]=2[O:21][CH2:20][C:19]1=[O:31])[CH3:17])[CH3:13]

Participants

6

Reactant 4

HCID 9845Trifluoroacetic anhydrideHCID 31294Carbamide PeroxideHCID 56183Ethyl 2-(6-acetyl-3-oxo-2,3-dihydro-4H-1,4-benzoxazin-4-yl)propanoateHCID 516892Sodium Bicarbonate

Product 1

HCID 867273432-(6-Acetoxy-3-oxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propionic acid ethyl ester

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a suspension of urea-hydrogen peroxide (5.93 g, 63 mmol) and NaHCO3 (5.93 g, 63 mmol) in DCM (60 mL) at 0° C. was added 2-(6-acetyl-3-oxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propionic acid ethyl ester (6.14 g, 21 mmol). The reaction mixture was stirred for 10 min and TFAA (5.84 mL, 42 mmol) was added dropwise. The reaction mixture was stirred at 0° C. for 1 h and then 3 days at ambient temperature. The reaction mixture was diluted with DCM (60 mL), quenched with saturated Na2S2O3 solution (30 mL) and washed with water (30 mL). The combined organic phase was dried over anhydrous Na2SO4, filtered and concentrated in vacuo to give 2-(6-acetoxy-3-oxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propionic acid ethyl ester, which was used in the next step directly without purification. TLC (eluting with 25% EtOAc/heptane) Rf=0.4.

Workup

  1. stirringThe reaction mixture was stirred at 0° C. for 1 h
  2. custom3 days
  3. customat ambient temperature
  4. customquenched with saturated Na2S2O3 solution (30 mL)
  5. washwashed with water (30 mL)
  6. dry with materialThe combined organic phase was dried over anhydrous Na2SO4
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-e3ac77bb7c7644c3938b9a63527b9dca
Source dataset
uspto-grants-2015_08
Patent number
US09115151B2

Reaction notes

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