Potassium Carbonate → Ethyl 6-nitro-3,4-dihydro-2H-1,4-benzoxazine-2-carboxylate

HRID 1448469Notes

Reaction equation

HRID 1448469 reaction equation
Br[CH:2]([CH2:8]Br)[C:3]([O:5][CH2:6][CH3:7])=[O:4].C(=O)([O-])[O-].[K+].[K+].[N+:16]([C:19]1[CH:24]=[CH:23][C:22]([OH:25])=[C:21]([NH2:26])[CH:20]=1)([O-:18])=[O:17]>CC(C)=O>[N+:16]([C:19]1[CH:24]=[CH:23][C:22]2[O:25][CH:2]([C:3]([O:5][CH2:6][CH3:7])=[O:4])[CH2:8][NH:26][C:21]=2[CH:20]=1)([O-:18])=[O:17]

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 97945Ethyl 2,3-dibromopropionateHCID 36133892-Amino-4-Nitrophenol

Product 1

HCID 20379906Ethyl 6-nitro-3,4-dihydro-2H-1,4-benzoxazine-2-carboxylate

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

29.2 g of ethyl 2,3-dibromopropionate was added dropwise to a refluxing mixture of 19 g of anhydrous potassium carbonate, 70.9 g of 4-nitro-2-aminophenol and 500 ml of dry acetone. This procedure was repeated thrice. The reaction mixture was refluxed for 17 hours, then filtered. The solvent was evaporated from the filtrate under reduced pressure. The residue was washed with dilute sodium hydroxide solution, extracted with ether, then with methylene chloride. The solvent was evaporated separately from each extract. Thin layer chromatographic analysis indicated that the produce from each of the extracts was the same. The products was combined and recrystallized from ether to give 4, as a solid, m.p.: 88°-90° C.

Workup

  1. temperatureThe reaction mixture was refluxed for 17 hours
  2. filtrationfiltered
  3. customThe solvent was evaporated from the filtrate under reduced pressure
  4. washThe residue was washed with dilute sodium hydroxide solution
  5. extractionextracted with ether
  6. customThe solvent was evaporated separately from each extract
  7. customproduce from each of the extracts
  8. customrecrystallized from ether
  9. customto give 4

Sources & evidence

ORD record
ord-b80a57ffdb0d48b480d5b1fd6211d4a3
Source dataset
uspto-grants-1979_12
Patent number
US04180572

Reaction notes

Loading…