Cesium carbonate → 3-Oxo-3,4-dihydro-2H-benzo[b][1,4]oxazine-6-carbonitrile

HRID 1991423Notes

Reaction equation

HRID 1991423 reaction equation
[OH:1][C:2]1[CH:9]=[CH:8][C:5]([C:6]#[N:7])=[CH:4][C:3]=1[N+:10]([O-])=O.C([O-])([O-])=O.[Cs+].[Cs+].[CH2:19]([O:21]C(=O)C)[CH3:20].O>CN(C=O)C>[O:21]=[C:19]1[NH:10][C:3]2[CH:4]=[C:5]([C:6]#[N:7])[CH:8]=[CH:9][C:2]=2[O:1][CH2:20]1

Participants

5

Reactant 3

HCID 10796Cesium carbonateHCID 767584-Hydroxy-3-nitrobenzonitrileHCID 22728543Water ethylacetate

Product 1

HCID 106548133-Oxo-3,4-dihydro-2H-benzo[b][1,4]oxazine-6-carbonitrile

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

24 mmol of 4-Hydroxy-3-nitrobenzonitrile were dissolved in DMF. 1.1 eq of Cs2CO3 were added and the reaction stirred at rt for 15 min. 1.5 eq of ethylbromo acetate were added and the reaction mixture heated to 50° C. for 2 h. The intermediate was isolated via extraction from ethylacetate/water. The organic layer was separated and dried over Na2SO4. After evaporation the resulting solid was redissolved in MeOH and sat. NH4Cl (1:1). 8 g of Zn powder were added and the suspension stirred at rt for 2 h. The solid was filtered off and the organic layer evaporated. Ethylacetate was added and the organic layer washed with sat. NaHCO3. The organic layer was separated again, dried over Na2SO4 and reduced resulting in a light brown solid. MS(ISO): 175.2 (MH+)

Workup

  1. temperaturethe reaction mixture heated to 50° C. for 2 h
  2. customThe organic layer was separated
  3. dry with materialdried over Na2SO4
  4. customAfter evaporation the resulting solid
  5. dissolutionwas redissolved in MeOH
  6. addition8 g of Zn powder were added
  7. stirringthe suspension stirred at rt for 2 h
  8. filtrationThe solid was filtered off
  9. customthe organic layer evaporated
  10. additionEthylacetate was added
  11. washthe organic layer washed with sat. NaHCO3
  12. customThe organic layer was separated again
  13. dry with materialdried over Na2SO4
  14. customreduced resulting in a light brown solid

Sources & evidence

ORD record
ord-78367938b7b54987a7f5cd236233916c
Source dataset
uspto-grants-2010_01
Patent number
US07645776B2

Reaction notes

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