2H-1,4-benzoxazin-3(4H)-one → 3,4-Dihydro-2H-1,4-benzoxazine

HRID 1067991Notes

Reaction equation

HRID 1067991 reaction equation
[H-].[H-].[H-].[H-].[Li+].[Al+3].[O:7]1[C:12]2[CH:13]=[CH:14][CH:15]=[CH:16][C:11]=2[NH:10][C:9](=O)[CH2:8]1>C1COCC1>[O:7]1[C:12]2[CH:13]=[CH:14][CH:15]=[CH:16][C:11]=2[NH:10][CH2:9][CH2:8]1

Participants

4

Reactant 2

HCID 727572H-1,4-benzoxazin-3(4H)-oneHCID 21226445Aluminium lithium hydride2×

Product 1

HCID 5850963,4-Dihydro-2H-1,4-benzoxazine

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of LiAlH4 (34 mL, 1M in THF) is added dropwise via addition funnel to a cold (0° C.) solution of (2H)1,4-benzoxazin-3(4H)-one (5.04 g) in freshly distilled THF (110 mL). The LiAlH4 is added at such a rate to keep the reaction temperature below 10° C. The mixture is stirred at room temperature for 2 h and then is quenched successively with water (5 mL), 15% NaOH (5 mL), and water (5 mL) again. The resulting precipitate is filtered and the filtrate is concentrated in vacuo. The residue is dissolved in CH2Cl2 and dried (Na2SO4), filtered, and concentrated to afford the product benzomorpholine as a yellow oil which was used without further purification in the next step.

Workup

  1. customthe reaction temperature below 10° C
  2. customis quenched successively with water (5 mL), 15% NaOH (5 mL), and water (5 mL) again
  3. filtrationThe resulting precipitate is filtered
  4. concentrationthe filtrate is concentrated in vacuo
  5. dissolutionThe residue is dissolved in CH2Cl2
  6. dry with materialdried (Na2SO4)
  7. filtrationfiltered
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-51f502b509414165967068cb66053b2c
Source dataset
uspto-grants-2001_06
Patent number
US06248739B1

Reaction notes

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