Sodium Bicarbonate → 2H-1,2-Benzoxazin-3(4H)-one

HRID 375522

Reaction equation

HRID 375522 reaction equation
[O:1]=[C:2]1[NH:7]C2C=C([N+]([O-])=O)C=CC=2O[CH2:3]1.N[C:16]1[CH:21]=[C:20]([N+]([O-])=O)[CH:19]=[CH:18][C:17]=1[OH:25].C(=O)(O)[O-].[Na+]>C(C(C)=O)C(C)C>[O:25]1[C:17]2[CH:18]=[CH:19][CH:20]=[CH:21][C:16]=2[CH2:3][C:2](=[O:1])[NH:7]1

Participants

5

Reactant 3

HCID 516892Sodium BicarbonateHCID 27636836-Nitro-2H-1,4-benzoxazin-3(4H)-oneHCID 36133892-Amino-4-Nitrophenol

Product 1

HCID 199374482H-1,2-Benzoxazin-3(4H)-one

Reagents, catalysts & solvents 1

HCID 7909Methyl Isobutyl KetoneSolvent

Conditions

Temperature
5 °C

Procedure

3-Oxo-6-nitro-3,4-dihydro-2H-1,4-benzoxazine. A solution of 2-amino-4-nitrophenol (8.80 g), in methyl isobutyl ketone (30 mL) was treated with sodium bicarbonate (11.5 g) and distilled water (35 mL). The mixture was cooled to 5° C. under a nitrogen atmosphere, treated dropwise with chloroacetyl chloride (5.0 mL) and then heated to reflux for 18 hours. A brown solid was collected from the cooled mixture by filtration. The solid was dried under vacuum at 50° C. for 24 hours yielding benzoxazinone (10.5 g) as a brown solid; mp 235°-236° C.; MS: m/z=195(M+1); NMR: 4.76 (s,2), 7.14 (d,1), 7.74 (d,1), 7.82 (dd,1), 11.07 (broad s,1).

Workup

  1. distillationdistilled water (35 mL)
  2. additiontreated dropwise with chloroacetyl chloride (5.0 mL)
  3. temperatureheated
  4. temperatureto reflux for 18 hours
  5. filtrationA brown solid was collected from the cooled mixture by filtration
  6. customThe solid was dried under vacuum at 50° C. for 24 hours

Sources & evidence

ORD record
ord-d458ffb65c6f431db06977d623c64fbf
Source dataset
uspto-grants-1996_01
Patent number
US05486515

Linked notes

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