Water → 3-phenyl-3,4-dihydro-2H-1,4-benzoxazine

HRID 585423Notes

Reaction equation

HRID 585423 reaction equation
[C:1]1([C:7]2[CH2:8][O:9][C:10]3[CH:16]=[CH:15][CH:14]=[CH:13][C:11]=3[N:12]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[BH4-].[Na+].O>C(O)C>[C:1]1([CH:7]2[NH:12][C:11]3[CH:13]=[CH:14][CH:15]=[CH:16][C:10]=3[O:9][CH2:8]2)[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

5

Reactant 3

HCID 962WaterHCID 14817833-phenyl-2H-1,4-benzoxazineHCID 4311764Sodium borohydride

Product 1

HCID 124745723-phenyl-3,4-dihydro-2H-1,4-benzoxazineYield 93%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
90 °C

Procedure

To a slurry of 3-phenyl-2H-1,4-benzoxazine (17 g, 81.2 mmol) in 100 mL absolute ethanol is added sodium borohydride (6.07 g, 162.4 mmol) and water (25 mL). The mixture is heated at 90° C. for 2 h. The mixture is cooled and concentrated, then partitioned between CH2Cl2 and water. The organic layer is washed twice with water (200 mL), dried over magnesium sulfate and concentrated. The resulting oil is dried under high vacuum to give 15.95 g (93%) of 3-phenyl-3,4-dihydro-2H-1,4-benzoxazine.

Workup

  1. temperatureThe mixture is cooled
  2. concentrationconcentrated
  3. custompartitioned between CH2Cl2 and water
  4. washThe organic layer is washed twice with water (200 mL)
  5. dry with materialdried over magnesium sulfate
  6. concentrationconcentrated
  7. customThe resulting oil is dried under high vacuum

Sources & evidence

ORD record
ord-51ebeefcb5164534ac60432ba82c36e8
Source dataset
uspto-grants-2005_08
Patent number
US06932961B1

Reaction notes

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