Sodium Hydroxide → 10H-pyrazino[2,3-b][1,4]benzothiazine-8-carboxylic acid

HRID 1059360Notes

Reaction equation

HRID 1059360 reaction equation
[N:1]1[C:10]2[NH:9][C:8]3[CH:11]=[C:12]([C:15]([O:17]C)=[O:16])[CH:13]=[CH:14][C:7]=3[S:6][C:5]=2[N:4]=[CH:3][CH:2]=1.[OH-].[Na+]>CO>[N:1]1[C:10]2[NH:9][C:8]3[CH:11]=[C:12]([C:15]([OH:17])=[O:16])[CH:13]=[CH:14][C:7]=3[S:6][C:5]=2[N:4]=[CH:3][CH:2]=1

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 11747308methyl 10H-pyrazino[2,3-b][1,4]benzothiazine-8-carboxylate

Product 1

HCID 1867033910H-pyrazino[2,3-b][1,4]benzothiazine-8-carboxylic acidYield 100.4%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To 50 ml of a solution of 2 g of methyl 10H-pyrazino[2,3-b][1,4]benzothiazine-8-carboxylate in methanol was added 0.8 g of sodium hydroxide and the resulting mixture was heated under reflux for 1 hour. After distilling off the methanol under reduced pressure, a 1 N aqueous solution of hydrochloric acid was added thereto so as to adjust the pH value to 5 to 6. Then the mixture was extracted with ethyl acetate/dichloromethane and the organic layer was dried over anhydrous magnesium sulfate. After distilling off the solvent under reduced pressure, 1.9 g of the title compound was obtained as a yellow solid.

Workup

  1. temperaturethe resulting mixture was heated
  2. temperatureunder reflux for 1 hour
  3. distillationAfter distilling off the methanol under reduced pressure
  4. additiona 1 N aqueous solution of hydrochloric acid was added
  5. extractionThen the mixture was extracted with ethyl acetate/dichloromethane
  6. dry with materialthe organic layer was dried over anhydrous magnesium sulfate
  7. distillationAfter distilling off the solvent under reduced pressure

Sources & evidence

ORD record
ord-78c8d2a5e73e4dcba027d53035d17c93
Source dataset
uspto-grants-2003_02
Patent number
US06518423B1

Reaction notes

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