Potassium Bicarbonate → 7-Chloro-6-((E)-styryl)-4H-pyrido[3,2-b][1,4]oxazin-3-one

HRID 970385Notes

Reaction equation

HRID 970385 reaction equation
Br[C:2]1[C:3]([Cl:13])=[CH:4][C:5]2[O:6][CH2:7][C:8](=[O:12])[NH:9][C:10]=2[N:11]=1.[C:14]1(/[CH:20]=[CH:21]/B(O)O)[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.C(=O)([O-])O.[K+]>O1CCOCC1.O.C(OCC)(=O)C>[Cl:13][C:3]1[C:2](/[CH:21]=[CH:20]/[C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)=[N:11][C:10]2[NH:9][C:8](=[O:12])[CH2:7][O:6][C:5]=2[CH:4]=1

Participants

7

Reactant 3

HCID 516893Potassium BicarbonateHCID 5702628Styrylboronic acidHCID 858536946-Bromo-7-chloro-4H-pyrido[3,2-b][1,4]oxazin-3-one

Product 1

HCID 685638677-Chloro-6-((E)-styryl)-4H-pyrido[3,2-b][1,4]oxazin-3-oneYield 68.3%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8857Ethyl AcetateSolventHCID 312751,4-DioxaneSolvent

Procedure

6-Bromo-7-chloro-4H-pyrido[3,2-b][1,4]oxazin-3-one (15a) (22 g, 83.7 mmole) and trans-2-phenylvinylboronic acid (17.33 g, 117 mmole) were dissolved in 1,4-dioxane (300 mL) and the solution was degassed with argon. (Ph3P)4Pd (1.9 g, 2 mole %) was added, followed by a solution of potassium hydrogen carbonate (21 g, 210 mmole) in H2O (100 mL). The reaction was heated at reflux under argon overnight, then was cooled to room temperature and diluted with ethyl acetate (1 L). The solution was washed sequentially with H2O and brine, dried (Na2SO4), and concentrated in vacuo. The residue was slurried with chloroform (120 mL), then diluted with diethyl ether (100 mL). The precipitated product was collected by filtration and washed with ether to provide the product (16.4 g, 68%) as an off-white solid.

Workup

  1. customthe solution was degassed with argon
  2. addition(Ph3P)4Pd (1.9 g, 2 mole %) was added
  3. temperatureThe reaction was heated
  4. temperatureat reflux under argon overnight
  5. washThe solution was washed sequentially with H2O and brine
  6. dry with materialdried (Na2SO4)
  7. concentrationconcentrated in vacuo
  8. additiondiluted with diethyl ether (100 mL)
  9. filtrationThe precipitated product was collected by filtration
  10. washwashed with ether

Sources & evidence

ORD record
ord-5963729bff3d42fab5be1c4f08b003a4
Source dataset
uspto-grants-2007_12
Patent number
US07312212B2

Reaction notes

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