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

HRID 414636Notes

Reaction equation

HRID 414636 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.[N+:13]([O-])([OH:15])=[O:14]>S(=O)(=O)(O)O>[F:1][C:2]1[C:12]([N+:13]([O-:15])=[O:14])=[CH:11][C:5]2[NH:6][C:7](=[O:10])[CH2:8][O:9][C:4]=2[CH:3]=1

Participants

4

Reactant 2

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

Product 1

HCID 137312977-Fluoro-6-nitro-2H-1,4-benzoxazin-3(4H)-oneYield 82.7%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

A solution of 7-fluoro-2H-1,4-benzoxazin-3(4H)-one (2.0 g) in 80% aqueous sulfuric acid (30 ml) was cooled to 0° to 5° C., and 60% nitric acid (1.6 g) was gradually added thereto at 0° to 5° C. The resultant mixture was stirred at the same temperature for 30 minutes and poured onto ice water. The precipitated crystals were collected by filtration, washed with water and dried to give 7-fluoro-6-nitro-2H-1,4-benzoxazin-3(4H)-one (2.1 g) as pale brown crystals. m.p., 205.9° C. 1H-NMR (CDCl3 +DMSO-D6) δ ppm: 3.2 (1H, broad), 4.62 (2H, s), 6.76 (1H, d, J=10 Hz), 7.6 (1H, d, J=6 Hz).

Workup

  1. customat 0° to 5° C
  2. additionpoured onto ice water
  3. filtrationThe precipitated crystals were collected by filtration
  4. washwashed with water
  5. customdried

Sources & evidence

ORD record
ord-83176ecb1f40492db285baea42410e0a
Source dataset
uspto-grants-1988_12
Patent number
US04792605

Reaction notes

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