Methanol → Methyl 4-bromothiophene-2-carboxylate
Reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([C:7]([OH:9])=[O:8])[S:5][CH:6]=1.S(=O)(=O)(O)O.[CH3:15]O>>[Br:1][C:2]1[CH:3]=[C:4]([C:7]([O:9][CH3:15])=[O:8])[S:5][CH:6]=1Participants
4
Conditions
- Temperature
- 50 °C
Procedure
To a solution of 4-bromo-2-thiophenecarboxylic acid (25 g, 121 mmol) in methanol (241 ml) was added sulfuric acid (32 ml, 604 mmol). The resulting solution stirred at 50° C. over 4 d. The solution was partitioned between H2O-DCM and the aqueous phase was washed several times with DCM. The combined organic fractions were dried over Na2SO4, concentrated and used directly without further purification providing methyl 4-bromo-2-thiophenecarboxylate (26 g, 118 mmol, 97% yield), LCMS (ES) m/e 222 (M+H)+.
Workup
- customThe solution was partitioned between H2O-DCM
- washthe aqueous phase was washed several times with DCM
- dry with materialThe combined organic fractions were dried over Na2SO4
- concentrationconcentrated
- customused directly without further purification
Sources & evidence
- ORD record
- ord-23ed35e6e00840d487a5ba411bbf2917
- Source dataset
- uspto-grants-2012_09
- Patent number
- US08273782B2
Reaction notes
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