Reaktion #313287

Reaktionsgleichung

3-bromo-2-methyl-benzo[b]thiophene-7-carboxylic acid methoxy-methyl-amide

CH3MgBr

→

title compound

Ausbeute 81.0%

1-(3-Bromo-2-methyl-benzo[b]thiophen-7-yl)-ethanone

Ausbeute 81.0%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITat rt for 10 min
2. 2
   TemperaturIt is cooled to 0° C.
3. 3
   Sonstigequenched with sat. NH4C (10 mL)
4. 4
   workup.ADDITIONdiluted with H2O (20 mL)
5. 5
   workup.ADDITIONtreated with 0.1 M HCl (20 mL)
6. 6
   Extraktionextracted with EtOAc (2×40 mL)
7. 7
   TrocknenThe combined organic layers are dried with Na2SO4
8. 8
   Filtrationfiltered
9. 9
   Einengenconcentrated
10. 10
    SonstigePurification of the crude material by chromatography

Vorschrift

A solution of 3-bromo-2-methyl-benzo[b]thiophene-7-carboxylic acid methoxy-methyl-amide (2.02 g, 6.43 mmol) in THF (65 mL) is cooled to 0° C., treated with CH3MgBr (3.0 M, 2.4 mL, 7.1 mmol). The reaction is stirred at 0° C. for 10 min, then at rt for 10 min. It is cooled to 0° C., quenched with sat. NH4C (10 mL); diluted with H2O (20 mL); treated with 0.1 M HCl (20 mL); extracted with EtOAc (2×40 mL). The combined organic layers are dried with Na2SO4, filtered and concentrated. Purification of the crude material by chromatography gives the title compound (1.39 g, 5.18 mmol, 81%). 1H NMR (CDCl3): δ. 2.58 (s, 3H), 2.75 (s, 3H), 7.53 (t, J=7.9 Hz, 1H), 7.96 (d, J=7.9 Hz, 1H), 7.99 (d, J=7.5 Hz, 1H) ppm. ES-MS (m/z): calcd for C11H9BrOS (M+1)+: 270.2. found: 270.0.

Quelle