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

Some drops from a solution of 2-bromo-3-methylthiophene (1.5 g, 8.5 mmol) in dry diethyl ether was added to a suspension of magnesium (308 mg, 12.7 mmol, 1.5 equiv.) in dry diethyl ether until the Grignard reagent began to form and 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 temperature, and the mixture was refluxed for two hours. After cooling to room temperature, the mixture was quenched with saturated ammonium chloride solution and extracted with tert. butylmethyl ether. The combined organic extracts were washed with water, brine, dried over magnesiumsulfate-dihydrate, filtered and evaporated to give a yellow oil. After purification on silica gel, 490 mg of the title compound were obtained as a light yellow oil. GC-MS (EI): M=156

1. customto form
2. temperatureto reflux
3. additionThe remaining solution was added dropwise
4. temperaturethe mixture was refluxed for two hours
5. customthe mixture was quenched with saturated ammonium chloride solution
6. extractionextracted with tert. butylmethyl ether
7. washThe combined organic extracts were washed with water, brine
8. dry with materialdried over magnesiumsulfate-dihydrate
9. filtrationfiltered
10. customevaporated
11. customto give a yellow oil
12. customAfter purification on silica gel

ORD-Eintrag

ord-265b441da79247a884bec2a35fd4a725

Quelldatensatz

uspto-grants-2011_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07973051B2