Ethyl bromoacetate → 3-Oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine-6-carbaldehyde

HRID 1518017Notes

Reaction equation

HRID 1518017 reaction equation
C(O[C:4](=[O:17])[CH2:5][O:6][C:7]1[C:8]([N+:14]([O-])=O)=[N:9][C:10](Br)=[CH:11][CH:12]=1)C.BrC1N=C([N+]([O-])=O)[C:22]([OH:28])=CC=1.C([O-])([O-])=O.[K+].[K+].BrCC(OCC)=O>CC(C)=O.CCOCC>[O:17]=[C:4]1[CH2:5][O:6][C:7]2[CH:12]=[CH:11][C:10]([CH:22]=[O:28])=[N:9][C:8]=2[NH:14]1

Participants

7

Reactant 4

HCID 7748Ethyl bromoacetateHCID 11430Potassium CarbonateHCID 218738086-Bromo-2-nitropyridin-3-olHCID 59560649Ethyl (6-bromo-2-nitropyridin-3-yloxy)acetate

Product 1

HCID 218737373-Oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine-6-carbaldehydeYield 74%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 3283Diethyl EtherSolvent

Procedure

(6-Bromo-2-nitro-pyridin-3-yloxy)-acetic acid ethyl ester. To a suspension of 6-bromo-2-nitro-pyridin-3-ol (3.07 g, 14.0 mmol) in acetone (20 mL) was added K2CO3 (3.93 g, 28.0 mmol) and ethyl bromoacetate (1.55 mL, 14.0 mmol). The mixture was heated to reflux and stirred for 20 h. The resulting suspension was cooled to RT, diluted with Et2O (100 mL) and filtered. The filtrate was concentrated to afford 3.14 g (74%) of the title compound, which was used without further purification. MS (ESI): exact mass calculated for C9H9BrN2O5, 303.97; m/z found, 305.2 [M+H]+. 1H NMR (400 MHz, CDCl3): 7.67 (d, J=8.6, 1H), 7.35 (d, J=8.7, 1H), 4.78 (s, 2H), 4.27 (q, J=7.1, 2H), 1.30 (t, J=8.5, 3H).

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux
  3. filtrationfiltered
  4. concentrationThe filtrate was concentrated

Sources & evidence

ORD record
ord-076d71f5468d40b4bbb3c3c9cbeb24d5
Source dataset
uspto-grants-2012_07
Patent number
US08232391B2

Reaction notes

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