Methyl 5-bromothiophene-2-carboxylate → Methyl 5-(3-tert-butyl-4-methoxyphenyl)-2-thiophenecarboxylate

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Reaction Steps

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.

Provenance & Evidence