Ethyl Acetate → 3-(5-ethyl-2-pyridinyl)-2,2-dimethyl-2,3-dihydro-(4H)-1,3-benzoxazin-4-one

HRID 1740966Notes

Reaction equation

HRID 1740966 reaction equation
Cl[C:2]1[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=2[O:5][C:4]([CH3:13])([CH3:12])[N:3]=1.[CH2:14]([C:16]1[CH:17]=[N+:18]([O-])[CH:19]=[CH:20][CH:21]=1)[CH3:15].C(OCC)(=[O:25])C>C(Cl)Cl>[CH2:14]([C:16]1[CH:21]=[CH:20][C:19]([N:3]2[C:2](=[O:25])[C:7]3[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=3[O:5][C:4]2([CH3:13])[CH3:12])=[N:18][CH:17]=1)[CH3:15]

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 84685Pyridine, 3-ethyl-, 1-oxideHCID 6020844-chloro-2,2-dimethyl-2H-1,3-benzoxazine

Product 1

HCID 218344093-(5-ethyl-2-pyridinyl)-2,2-dimethyl-2,3-dihydro-(4H)-1,3-benzoxazin-4-oneYield 33%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A solution of 172 mg (0.87 mmol) of 4-chloro-2,2-dimethyl-(2H)-1,3-benzoxazine (K. Wachi and A. Terada, Chem. Pharm. Bull, 1980, 28, 465-472) and 215 mg (1.75 mmol) of 3-ethylpyridine N-oxide (S. Hibino and E. Sugino, J. Heterocycl Chem., 1990, 27, 175) in 1.6 mL of methylene chloride was heated to reflux for 9 h with stirring. After cooling the reaction, 30 mL ethyl acetate was added and the mixture was washed in succession with 10 mL saturated sodium bicarbonate and 10 mL of saturated aqueous sodium chloride. The organic solution was dried (sodium sulfate), decanted, and evaporated to give a yellow liquid. Flash column chromatography on 17 g of silica gel, eluting with 100 mL of 5% ethyl acetate/hexane and 500 mL of 7% ethyl acetate/hexane furnished 84 mg (33% yield) of 3-(5-ethyl-2-pyridinyl)-2,2-dimethyl-2,3-dihydro-(4H)-1,3-benzoxazin-4-one as a colorless syrup.

Workup

  1. temperatureto reflux for 9 h
  2. temperatureAfter cooling
  3. additionwas added
  4. washthe mixture was washed in succession with 10 mL saturated sodium bicarbonate and 10 mL of saturated aqueous sodium chloride
  5. dry with materialThe organic solution was dried (sodium sulfate)
  6. customdecanted
  7. customevaporated
  8. customto give a yellow liquid
  9. washFlash column chromatography on 17 g of silica gel, eluting with 100 mL of 5% ethyl acetate/hexane and 500 mL of 7% ethyl acetate/hexane

Sources & evidence

ORD record
ord-371d704204f246d19d9a55bfd8ea0d24
Source dataset
uspto-grants-1999_10
Patent number
US05972975

Reaction notes

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