Ethanol → Bromo-4-oxo-3,4-dihydro-phthalazine-6-carboxylic acid ethyl ester

HRID 1783721Notes

Reaction equation

HRID 1783721 reaction equation
S(=O)(=O)(O)O.[Br:6][C:7]1[C:16]2[C:11](=[CH:12][C:13]([C:17]([OH:19])=[O:18])=[CH:14][CH:15]=2)[C:10](=[O:20])[NH:9][N:8]=1.[CH3:21][CH2:22]O>>[CH2:21]([O:18][C:17]([C:13]1[CH:12]=[C:11]2[C:16](=[CH:15][CH:14]=1)[C:7]([Br:6])=[N:8][NH:9][C:10]2=[O:20])=[O:19])[CH3:22]

Participants

4

Reactant 3

HCID 702EthanolHCID 1118Sulfuric AcidHCID 211065111-Bromo-4-oxo-3,4-dihydro-phthalazine-6-carboxylic acid

Product 1

HCID 57856207Bromo-4-oxo-3,4-dihydro-phthalazine-6-carboxylic acid ethyl esterYield 31%

Procedure

Concentrated sulfuric acid (40 ml) was added to a stirred solution of 1-bromo-4-oxo-3,4-dihydro-phthalazine-6-carboxylic acid (85 g, 0.32 mol) in EtOH (500 ml) and the mixture was heated to reflux for 48 hours. After this time, the reaction mixture was cooled and the resulting precipitate was filtered. The precipitate was partitioned between EtOAc (1 L) and saturated NaHCO3 (500 ml), the organic layer was separated and washed with water (500 ml) before being dried (MgSO4), filtered and concentrated under vacuum to give the title compound (30 g, 31% yield) as a white solid. Tr=1.23 min, m/z (ES+) (M+H)+ 297 & 299

Workup

  1. temperaturethe mixture was heated
  2. temperatureto reflux for 48 hours
  3. temperatureAfter this time, the reaction mixture was cooled
  4. filtrationthe resulting precipitate was filtered
  5. customThe precipitate was partitioned between EtOAc (1 L) and saturated NaHCO3 (500 ml)
  6. customthe organic layer was separated
  7. washwashed with water (500 ml)
  8. dry with materialbefore being dried (MgSO4)
  9. filtrationfiltered
  10. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-51191748fff74f2bbc598516fa53700f
Source dataset
uspto-grants-2009_03
Patent number
US07501410B2

Reaction notes

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