Methyl 5-bromothiophene-2-carboxylate → Methyl 5-(3-tert-butyl-4-methoxyphenyl)-2-thiophenecarboxylate
Reaction equation
[C:1]([C:5]1[CH:6]=[C:7](Br)[CH:8]=[CH:9][C:10]=1[O:11][CH3:12])([CH3:4])([CH3:3])[CH3:2].[Mg].Br[C:16]1[S:20][C:19]([C:21]([O:23][CH3:24])=[O:22])=[CH:18][CH:17]=1>C1COCC1.[Cl-].[Zn+2].[Cl-]>[C:1]([C:5]1[CH:6]=[C:7]([C:16]2[S:20][C:19]([C:21]([O:23][CH3:24])=[O:22])=[CH:18][CH:17]=2)[CH:8]=[CH:9][C:10]=1[O:11][CH3:12])([CH3:4])([CH3:3])[CH3:2]Participants
Procedure
A solution of 2 g (8.2 mmol) of 3-tert-butyl-4-methoxybromobenzene is added dropwise to a suspension of 300 mg (12 mmol) of magnesium in 10 ml of THF. Once the addition is complete, the mixture is refluxed for one hour. At room temperature, 1.35 g (9.9 mmol) of anhydrous zinc chloride are added and the mixture is stirred for one hour. 1.2 g (5.5 mmol) of methyl 5-bromo-2-thiophenecarboxylate and 60 mg (0.12 mmol) of the NiCl2/DPPE complex are then added successively and the mixture is left stirring at room temperature for 12 hours. The reaction medium is poured into ice-water and extracted with ethyl ether and the organic phase is separated out after settling has taken place, dried over magnesium sulphate and evaporated. The residue obtained is chromatographed on a column of silica eluted with a mixture of hexane and dichloromethane (50/50% by volume). After evaporation of the solvents, 1.56 g (93%) of the expected methyl ester are collected, with a melting point of 94-5° C.
Workup
- additionOnce the addition
- temperaturethe mixture is refluxed for one hour
- waitthe mixture is left
- stirringstirring at room temperature for 12 hours
- extractionextracted with ethyl ether
- customthe organic phase is separated out after settling
- dry with materialdried over magnesium sulphate
- customevaporated
- customThe residue obtained
- customis chromatographed on a column of silica
- washeluted with a mixture of hexane and dichloromethane (50/50% by volume)
- customAfter evaporation of the solvents, 1.56 g (93%) of the expected methyl ester
- customare collected, with a melting point of 94-5° C.
Sources & evidence
- ORD record
- ord-c683eb7587ae411e9933cde239ecae4f
- Source dataset
- uspto-grants-2004_11
- Patent number
- US06825360B1
Reaction notes
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