Reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[CH:8]=[C:7]([C:12]([OH:14])=[O:13])[CH:6]=[CH:5]2.[CH2:15](O)[CH3:16].S(=O)(=O)(O)O>>[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[CH:8]=[C:7]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[CH:6]=[CH:5]2Participants
Procedure
To a solution of 6-bromo-2-naphthalenecarboxylic acid (Compound M) 3.1 g, (12.43 mmol) in ethanol (30 ml, 23.55 g, 511.0 mmol) was added 18M sulfuric acid (2 ml). The solution was refluxed for 30 minutes, cooled to room temperature, and the reaction mixture partitioned between pentane (100 ml) and water (100 ml). The aqueous phase was extracted with pentane (100 ml) and the combined organic layers washed with saturated aqueous NaCl (100 ml), dried (MgSO4), and concentrated to yield an off-white solid. Purification by flash chromatography (silica, 10% EtOAc-hexane) afforded the title compound as a white solid. 1H NMR (CDCl3): δ 8.58 (1H, br s), 8.10 (1H, dd, J=1.7, 9 Hz), 8.06 (1H, d, J=2 Hz), 7.83 (1H, d, J=9 Hz), 7.80 (1H, d, J=9 Hz), 7.62 (1H, dd, J=2,9 Hz).
Workup
- temperatureThe solution was refluxed for 30 minutes
- customthe reaction mixture partitioned between pentane (100 ml) and water (100 ml)
- extractionThe aqueous phase was extracted with pentane (100 ml)
- washthe combined organic layers washed with saturated aqueous NaCl (100 ml)
- dry with materialdried (MgSO4)
- concentrationconcentrated
- customto yield an off-white solid
- customPurification by flash chromatography (silica, 10% EtOAc-hexane)
Sources & evidence
- ORD record
- ord-773a5f9288db4b739399d16c782e205a
- Source dataset
- uspto-grants-2005_09
- Patent number
- US06942980B1
Linked notes
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