Nitric Acid → 8-methyl-6-nitro-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

HRID 723251Notes

Reaction equation

HRID 723251 reaction equation
[CH3:1][C:2]1[C:7]2[NH:8][C:9](=[O:13])[O:10][C:11](=[O:12])[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[NH:8][C:9](=[O:13])[O:10][C:11](=[O:12])[C:6]=2[CH:5]=[C:4]([N+:14]([O-:16])=[O:15])[CH:3]=1

Participants

4

Reactant 2

HCID 944Nitric AcidHCID 27598708-methyl-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

Product 1

HCID 218865708-methyl-6-nitro-2,4-dihydro-1H-3,1-benzoxazine-2,4-dioneYield 89%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

To a flask charged with 8-methyl-1H-benzo[d][1,3]oxazine-2,4-dione ((Example 295: step a) 9.27 g, 52.4 mmol) in an ice-water bath was added concentrated H2SO4 (90 mL) over 5 minutes period. After stirring for 10 minutes, fuming HNO3 (2.9 mL) was added over 15 minutes. The reaction mixture was stirred for further 30 minutes in the ice-water bath, 30 minutes at ambient temperature, then slowly poured into ice with stirring. The solid was collected, washed with H2O (3×50 mL), and dried in high vacuum to give the title compound (10.4 g, 89% yield) as a yellow solid. 1H NMR (DMSO) δ 11.65 (br s, 1H), 8.46–8.43 (m, 2H), 2.44 (s, 3H).

Workup

  1. additionslowly poured into ice
  2. stirringwith stirring
  3. customThe solid was collected
  4. washwashed with H2O (3×50 mL)
  5. customdried in high vacuum

Sources & evidence

ORD record
ord-95540867304644efac2deb961d931850
Source dataset
uspto-grants-2006_11
Patent number
US07138530B2

Reaction notes

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