Nitric Acid → 7-Fluoro-6-nitro-2H-1,4-benzoxazin-3(4H)-one

HRID 1940486Notes

Reaction equation

HRID 1940486 reaction equation
[F:1][C:2]1[CH:12]=[CH:11][C:5]2[NH:6][C:7](=[O:10])[CH2:8][O:9][C:4]=2[CH:3]=1.OS(O)(=O)=O.[N+:18]([O-])([OH:20])=[O:19]>CCOC(C)=O>[F:1][C:2]1[C:12]([N+:18]([O-:20])=[O:19])=[CH:11][C:5]2[NH:6][C:7](=[O:10])[CH2:8][O:9][C:4]=2[CH:3]=1

Participants

5

Reactant 3

HCID 944Nitric AcidHCID 1118Sulfuric Acid2×HCID 137312957-fluoro-3,4-dihydro-2H-1,4-benzoxazin-3-one

Product 1

HCID 137312977-Fluoro-6-nitro-2H-1,4-benzoxazin-3(4H)-one

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

To a stirred solution of the compound of Step B, Example 3, (48.9 gm, 292.8 mmol) and concentrated H2SO4 (100 mL), under N2, was added a 26 mL mixture of HNO3 (69-71%) and concentrated H2SO4 dropwise at 25°-35° C. (ice-bath). The resultant solution was stirred at room temperature for 10 minutes. 400 mL of ice water was added portionwise to the solution at 0° C. (ice-bath) followed by the addition of EtOAc (1.5 L). The organic layer was separated, dried (MgSO4) and evaporated to dryness to give the title compound of Step C as a tan solid (60.0 gm), 96%; m.p. 200°-202° C.; IR (nujol, cm-1): 1703.5 (C=O); 1H NMR δ: 4.79 (s,2H), 7.26-7.29 (d,1H), 7.63-7.64 (d,1H), 11.05 (s,1H).

Workup

  1. customThe organic layer was separated
  2. dry with materialdried (MgSO4)
  3. customevaporated to dryness

Sources & evidence

ORD record
ord-d13d6d60d2cc4384a678e819ae2ac78f
Source dataset
uspto-grants-1997_12
Patent number
US05700761

Reaction notes

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