Ethyl Acetate → 2,3-Dihydro-1,4-benzothiazine

HRID 351580Notes

Reaction equation

HRID 351580 reaction equation
[S:1]1[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=2[NH:4][C:3](=O)[CH2:2]1.[H-].[Al+3].[Li+].[H-].[H-].[H-].C(OCC)(=O)C>O1CCCC1>[S:1]1[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=2[NH:4][CH2:3][CH2:2]1

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 213964H-1,4-Benzothiazin-3-oneHCID 21226445Aluminium lithium hydride

Product 1

HCID 1510642,3-Dihydro-1,4-benzothiazineYield 96.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of (2H)1,4-benzothiazin-3(4H)-one (20.0 g, 121.1 mmol) in anhydrous tetrahydrofuran (100 mL) was added to a stirred suspension of lithium aluminum hydride in anhydrous tetrahydrofuran (80 mL) under nitrogen at 0° C. The mixture was heated at reflux for 2 hrs and then poured into a mixture of ethyl acetate (300 mL) and ice (500 g). The organic layer was separated and the aqueous layer extracted with ethyl acetate. The combined organic layer was dried and concentrated under reduced pressure to provide 17.68 g (96.5%) of the desired compound which was used without further purification.

Workup

  1. temperatureThe mixture was heated
  2. temperatureat reflux for 2 hrs
  3. customThe organic layer was separated
  4. extractionthe aqueous layer extracted with ethyl acetate
  5. customThe combined organic layer was dried
  6. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-75c8e7adbdc94062972659bb58dc2fe8
Source dataset
uspto-grants-2004_06
Patent number
US06743785B2

Reaction notes

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