2-Bromo-3-methylthiophene → 2-(2-Methoxy-ethyl)-3-methyl-thiophene

Beteiligte Stoffe

Reaktionsschritte

A part of a solution containing 2-bromo-3-methylthiophene CAS14282-76-9 (1.5 g, 8.5 mmol) in dry diethyl ether was added drop-wise to a suspension of magnesium (308 mg, 12.7 mmol, 1.5 equiv.) in dry diethyl ether, until the mixture started to reflux. The remaining solution was added dropwise. A solution of toluene-4-sulfonic acid 2-methoxy-ethyl ester (2.9 g, 12.7 mmol, 1.5 equiv.) in dry diethyl ether was added dropwise at room temp., then the mixture was refluxed for two hours. After cooling down to room temp., the mixture was quenched with ammonium chloride solution saturated and extracted with tert. butylmethyl ether. The combined organic extracts were washed with water and brine, dried over magnesiumsulfate-dihydrate and purified on silica gel with eluent n-heptane and tert.butylmethyl ether. The title compound was obtained as light yellow oil: 490 mg, GC-MS (EI) M=156.

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