Isopropenyl acetate → 4-Methyl-7-(2-oxopropyl)-2H-pyrido[3,2-b]-1,4-oxazin-3(4H)-one

HRID 1607559Notes

Reaction equation

HRID 1607559 reaction equation
[CH3:1][N:2]1[C:7](=[O:8])[CH2:6][O:5][C:4]2[CH:9]=[C:10](Br)[CH:11]=[N:12][C:3]1=2.C1(C)C=CC=CC=1P(C1C=CC=CC=1C)C1C=CC=CC=1C.C([O:39][C:40]([CH3:42])=[CH2:41])(=O)C.C[O-].C([Sn+](CCCC)CCCC)CCC>C1C=CC=CC=1.C([O-])(=O)C.[Pd+2].C([O-])(=O)C>[CH3:1][N:2]1[C:7](=[O:8])[CH2:6][O:5][C:4]2[CH:9]=[C:10]([CH2:41][C:40](=[O:39])[CH3:42])[CH:11]=[N:12][C:3]1=2

Participants

7

Reactant 4

HCID 7916Isopropenyl acetateHCID 80271Tri-o-tolylphosphineHCID 11964040Methoxytri-n-butylstannaneHCID 159259847-Bromo-4-methyl-4H-pyrido[3,2-b][1,4]oxazin-3-one

Product 1

HCID 159259854-Methyl-7-(2-oxopropyl)-2H-pyrido[3,2-b]-1,4-oxazin-3(4H)-one

Reagents, catalysts & solvents 2

HCID 167845palladium(II) acetateCatalystHCID 241BenzeneSolvent

Conditions

Temperature
70 °C

Procedure

4-Methyl-7-bromo-2H-pyrido[3,2-b]-1,4-oxazin-3(4H)-one (3 g) (0.012 mole) in 80 ml of benzene is treated with 365 mg tri-o-tolylphosphine, 138 mg palladium acetate, 1.87 g (0.018 mole) of isopropenyl acetate and 5.9 g (0.18 mole) of tributyltin methoxide. The mixture is heated to 70° C. for 25 hours. The reaction mixture is then quenched with 20 ml sat. ammonium chloride and diluted with 50 ml ethyl acetate. The organic phase separates, dried over sodium sulfate and concentrated to dryness. The residue is dissolved in methylene chloride, washed with sat. KF solution, filtered through a cotton plug, dried over sodium sulfate and concentrated to dryness to obtain crude product. This is chromatographed using 200×60 mm SiO2,EtOAc (100%) as eluent. The desired product is identified by NMR and used directly in the next step.

Workup

  1. customThe reaction mixture is then quenched with 20 ml sat. ammonium chloride
  2. additiondiluted with 50 ml ethyl acetate
  3. dry with materialThe organic phase separates, dried over sodium sulfate
  4. concentrationconcentrated to dryness
  5. dissolutionThe residue is dissolved in methylene chloride
  6. washwashed with sat. KF solution
  7. filtrationfiltered through a cotton plug
  8. dry with materialdried over sodium sulfate
  9. concentrationconcentrated to dryness
  10. customto obtain crude product
  11. customThis is chromatographed

Sources & evidence

ORD record
ord-24f915ae5032459f8d4bfa33df49624f
Source dataset
uspto-grants-1989_09
Patent number
US04866074

Reaction notes

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