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

HRID 1518019Notes

Reaction equation

HRID 1518019 reaction equation
[CH:1]([C:9]1[CH:10]=[CH:11][C:12]2[O:13][CH2:14][C:15](=[O:19])[NH:16][C:17]=2[N:18]=1)=CC1C=CC=CC=1.BrC1C=CC2[O:25]CC(=O)NC=2N=1.C1(/C=C/B(O)O)C=CC=CC=1.C([O-])([O-])=O.[K+].[K+]>O1CCOCC1.O.CCOC(C)=O.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[O:19]=[C:15]1[CH2:14][O:13][C:12]2[CH:11]=[CH:10][C:9]([CH:1]=[O:25])=[N:18][C:17]=2[NH:16]1

Participants

9

Reactant 4

HCID 11430Potassium CarbonateHCID 5702628Styrylboronic acidHCID 218737726-Bromo-2H-pyrido[3,2-B][1,4]oxazin-3(4H)-oneHCID 684438466-Styryl-4H-pyrido[3,2-b][1,4]oxazin-3-one

Product 1

HCID 218737373-Oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine-6-carbaldehydeYield 43%

Reagents, catalysts & solvents 4

HCID 178418397HCID 178418397, compoundCatalystHCID 962WaterSolventHCID 8857Ethyl AcetateSolventHCID 312751,4-DioxaneSolvent

Procedure

6-Styryl-4H-pyrido[3,2-b][1,4]oxazin-3-one. To a solution of 6-bromo-4H-pyrido[3,2-b][1,4]oxazin-3-one (3.2 g, 14 mmol) in 1,4-dioxane (80 mL) was added trans-2-phenylvinylboronic acid (2.1 g, 14 mmol). After the reaction mixture was degassed with nitrogen, tetrakis(triphenylphosphine)palladium(0) (0.129 g, 0.112 mmol) and a solution of K2CO3 (3.7 g, 27 mmol) in H2O (10.7 mL) were added. The reaction was heated at reflux for 17 h, then cooled to RT, and diluted with EtOAc (300 mL). The organic layer was separated, washed with H2O (300 mL), brine (300 mL), dried (Na2SO4), and concentrated. The solid residue was purified on SiO2 (5-10% EtOAc/CHCl3) to provide 1.5 g (43%) of the title compound as a solid. MS (ESI): exact mass calculated for C15H12N2O2, 252.09; m/z found, 253.2 [M+H]+. 1H NMR (400 MHz, CDCl3): 7.53-7.00 (m, 9H), 4.66 (d, J=6.9, 2H).

Workup

  1. temperatureThe reaction was heated
  2. temperatureat reflux for 17 h
  3. customThe organic layer was separated
  4. washwashed with H2O (300 mL), brine (300 mL)
  5. dry with materialdried (Na2SO4)
  6. concentrationconcentrated
  7. customThe solid residue was purified on SiO2 (5-10% EtOAc/CHCl3)

Sources & evidence

ORD record
ord-1aa77bbfe8b843108dce86dfb2b79dad
Source dataset
uspto-grants-2012_07
Patent number
US08232391B2

Reaction notes

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