Water → 7-Methyl-3,4-dihydro-2H-1,4-benzoxazine

HRID 717762Notes

Reaction equation

HRID 717762 reaction equation
[OH:1][C:2]1[CH:8]=[C:7]([CH3:9])[CH:6]=[CH:5][C:3]=1[NH2:4].C(=O)([O-])[O-].[K+].[K+].Br[CH2:17][CH2:18]Br.O>C1COCC1>[CH3:9][C:7]1[CH:6]=[CH:5][C:3]2[NH:4][CH2:18][CH2:17][O:1][C:2]=2[CH:8]=1

Participants

6

Reactant 4

HCID 962WaterHCID 78391,2-DibromoethaneHCID 11430Potassium CarbonateHCID 760822-Amino-5-methylphenol

Product 1

HCID 125105457-Methyl-3,4-dihydro-2H-1,4-benzoxazineYield 57.6%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of 2-hydroxy-4-methyl aniline (5.0 g, 40 mmol), potassium carbonate (16.56 g, 120 mmol) and 1,2-dibromoethane (3.8 g, 20 mmol) in THF (20 mL) was heated at 100° C. in pressure-gauge-steel vessel for 16 h. The completion of reaction was monitored by LCMS. The reaction mixture was poured into water (40 mL) and extracted with EtOAc (250 mL). The organic layer was dried over sodium sulfate, evaporated and the residue purified by column chromatography to obtain 1.72 g of 3,4-dihydro-7-methyl-2H-benzo[b][1,4]oxazine (free base).

Workup

  1. customThe completion of reaction
  2. extractionextracted with EtOAc (250 mL)
  3. dry with materialThe organic layer was dried over sodium sulfate
  4. customevaporated
  5. customthe residue purified by column chromatography

Sources & evidence

ORD record
ord-c5e7979838144ffc80ece45c7de1b075
Source dataset
uspto-grants-2015_11
Patent number
US09193728B2

Reaction notes

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