Methanol → Methyl 5-chlorothiophene-2-carboxylate
Reaction equation
[Cl:1][C:2]1[S:6][C:5]([C:7]([OH:9])=[O:8])=[CH:4][CH:3]=1.S(=O)(=O)(O)O.O.[CH3:16]O>>[Cl:1][C:2]1[S:6][C:5]([C:7]([O:9][CH3:16])=[O:8])=[CH:4][CH:3]=1Participants
5
Conditions
- Temperature
- 50 °C
Procedure
To a solution of 5-chloro-2-thiophenecarboxylic acid (10 g, 61.5 mmol) in methanol (200 ml) was added sulfuric acid (0.983 ml, 18.45 mmol). The resulting solution stirred at 50° C. overnight. H2O (50 mL) was added and the reaction was cooled to 0° C. in an ice-bath. The pH was adjusted to ˜12 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 5-chloro-2-thiophenecarboxylate (7.2 g, 40.8 mmol, 66.3% yield): LCMS (ES) m/z 178 (M+H)+.
Workup
- temperaturethe reaction was cooled to 0° C. in an ice-bath
- 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-6fc64c711d9d4bd6adb766a00189a1d3
- Source dataset
- uspto-grants-2013_11
- Patent number
- US08592475B2
Reaction notes
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