Propargyl bromide → 2H-1,4-benzoxazin-3(4H)-one

HRID 1440146Notes

Reaction equation

HRID 1440146 reaction equation
ClC1C([C:12]2[C:13](F)=[CH:14][C:15]3[O:20][CH2:19][C:18](=[O:21])[NH:17][C:16]=3[CH:22]=2)=NN(C)C=1C(F)(F)F.C([O-])([O-])=O.[K+].[K+].C(Br)C#C>CC(C)=O.O>[O:20]1[C:15]2[CH:14]=[CH:13][CH:12]=[CH:22][C:16]=2[NH:17][C:18](=[O:21])[CH2:19]1

Participants

6

Reactant 3

HCID 7842Propargyl bromideHCID 11430Potassium CarbonateHCID 194367686-(4-chloro-1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl)-7-fluoro-2H-1,4-benzoxazin-3(4H)-one

Product 1

HCID 727572H-1,4-benzoxazin-3(4H)-oneYield 231.5%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 962WaterSolvent

Conditions

Temperature
40 °C

Procedure

At 25° C., 3.0 g (8.6 mmole) of the product of step A, 1.22 g (6.0 mmole) K2CO3 and 0.79 mL (8.8 mmole) 80% propargyl bromide were slurried in 50 mL acetone. The reaction was stirred at 40° C. for 6 hours. The reaction was cooled, diluted with 100 mL cold water, and extracted four times with ethyl acetate. The ethyl acetate extracts were washed with brine, dried over anhydrous MgSO4, and stripped in vacuo. The residue was recrystallized from methylcyclohexane to give 2.97 g (89%) of 2H-1,4-benzoxazin-3(4H)-one, 6-(4-chloro-1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl)-7-fluoro-4-(2-propynyl)-2H-1,4-benzoxazin-3(4H)-one as a beige solid, mp 142°-143° C.

Workup

  1. customAt 25° C.
  2. temperatureThe reaction was cooled
  3. extractionextracted four times with ethyl acetate
  4. washThe ethyl acetate extracts were washed with brine
  5. dry with materialdried over anhydrous MgSO4
  6. customThe residue was recrystallized from methylcyclohexane

Sources & evidence

ORD record
ord-2f78f8c3a0a54044a71e4c0e7fdc89c9
Source dataset
uspto-grants-1996_03
Patent number
US05496956

Reaction notes

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