Reaktionsgleichung
[Cl:1][C:2]1[C:3]([O:12][CH3:13])=[CH:4][C:5]2[CH:9]=[CH:8][S:7][C:6]=2[C:10]=1[Cl:11].C([Li])CCC.[C:19](OC(=O)C)(=[O:21])[CH3:20].Cl>O1CCCC1.C(OCC)C>[C:19]([C:8]1[S:7][C:6]2[C:10]([Cl:11])=[C:2]([Cl:1])[C:3]([O:12][CH3:13])=[CH:4][C:5]=2[CH:9]=1)(=[O:21])[CH3:20]Komponenten
Edukt 4
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 2
Versuchsvorschrift
To a solution of 5.0 g of 6,7-dichloro-5-methoxybenzo[b]thiophene in 30 ml of dry tetrahydrofuran and 10 ml dry ethyl ether under nitrogen at -20° is added 11.7 ml of 2.2M n-butyllithium, while the temperature is maintained at -20°. After stirring for 2 hours at this temperature, the reaction mixture is added dropwise through a transfer needle to a stirred solution of 22 ml of freshly distilled acetic anhydride in 40 ml of dry tetrahydrofuran at -20°. Five minutes after the addition, the reaction mixture is poured onto 100 ml 10% hydrochloric acid. The mixture is extracted twice with dichloromethane, the organic layers are collected and dried and the solvent is removed to give a solid. The solid is washed with ethyl ether to give 1.5 g of 2-acetyl-6,7-dichloro-5-methoxybenzo[b]thiophene as a fluffy solid. Recrystallization of the residue obtained by evaporation of the filtrate from ethyl ether-hexane gives an additional 0.6 g of 2-acetyl-6,7-dichloro-5-methoxybenzo[b]thiophene.
Aufarbeitung
- temperaturewhile the temperature is maintained at -20°
- additionFive minutes after the addition
- extractionThe mixture is extracted twice with dichloromethane
- customthe organic layers are collected
- customdried
- customthe solvent is removed
- customto give a solid
- washThe solid is washed with ethyl ether
Quellen und Nachweise
- ORD-Eintrag
- ord-dc670d62dc7a4451a677f670d896a64e
- Quelldatensatz
- uspto-grants-1985_07
- Patentnummer
- US04528399
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