Nitric Acid → 5-Methyl-6-nitro-1H-benzo[d][1,3]oxazine-2,4-dione

HRID 1840861Notes

Reaction equation

HRID 1840861 reaction equation
[CH3:1][C:2]1[C:7]2[C:8](=[O:13])[O:9][C:10](=[O:12])[NH:11][C:6]=2[CH:5]=[CH:4][CH:3]=1.[N+:14]([O-])([OH:16])=[O:15]>OS(O)(=O)=O>[CH3:1][C:2]1[C:7]2[C:8](=[O:13])[O:9][C:10](=[O:12])[NH:11][C:6]=2[CH:5]=[CH:4][C:3]=1[N+:14]([O-:16])=[O:15]

Participants

4

Reactant 2

HCID 944Nitric AcidHCID 104875225-methyl-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

Product 1

HCID 219011545-Methyl-6-nitro-1H-benzo[d][1,3]oxazine-2,4-dione

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 5-methyl-4H-3,1-benzoxazin-2,4-dione (20 g, 113 mmol) in 150 mL of concentrated H2SO4, cooled to −15° C., was added 7.83 g of 90% w/w HNO3 (in 30 mL of conc. H2SO4) dropwise at such a rate to keep the internal temperature below 5° C. After the addition was complete, the reaction was stirred at 0° C. for an additional 20 minutes then quenched by pouring the reaction mixture over crushed ice. Following further dilution with water, the resulting precipitate was filtered, washed with water, resuspended in water then filtered and washed again with water affording 15.1 g (60%) of 5-methyl-6-nitro-4H-3,1-benzoxazin-2,4-dione, after drying: Anal. Calc'd. for C9H6N2O5: C, 48.66; H, 2.72; N, 12.61. Found: C, 48.19; H, 2.54; N, 12.51.

Workup

  1. customthe internal temperature below 5° C
  2. additionAfter the addition
  3. customthen quenched
  4. additionby pouring the reaction mixture
  5. customover crushed ice
  6. filtrationthe resulting precipitate was filtered
  7. washwashed with water
  8. filtrationthen filtered
  9. washwashed again with water affording 15.1 g (60%) of 5-methyl-6-nitro-4H-3,1-benzoxazin-2,4-dione
  10. customafter drying

Sources & evidence

ORD record
ord-0b26b609e1d14b6390bb1269a4228386
Source dataset
uspto-grants-2004_01
Patent number
US06683077B2

Reaction notes

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