Reaktion #468488

Reaktionsgleichung

methyl chloroformate

Sec-butyllithium

6-bromo-1-ethylindole

compound

6-Bromo-1-ethylindole

→

subtitle compound

6-Methoxycarbonyl-1-ethylindole

Lösungsmittel

diethyl ether

cyclohexane

diethylether

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeAfter 1 hour the cooling bath was removed
2. 2
   workup.ADDITIONAfter a further 1 hour the mixture was poured into brine
3. 3
   Extraktionextracted with ethyl acetate
4. 4
   TrocknenThe organic layers were dried (MgSO4 )
5. 5
   Einengenconcentrated in vacuo
6. 6
   Sonstigeto give a yellow oil
7. 7
   WaschenFlash column chromatography (elution with 90% hexane, 10% ethyl acetate)

Vorschrift

Sec-butyllithium (9.4 ml of a 1.3M solution in cyclohexane) was added to a stirred solution of 6-bromo-1-ethylindole [the compound of step (a), 2.5 g]in diethylether (20 ml) at −78° C. under a nitrogen atmosphere. After 30 minutes this solution was transferred by cannula to a stirred solution of methyl chloroformate (1.29 ml, 16.74 mmol) in diethyl ether (8 ml) at −78° C. under a nitrogen atmosphere. After 1 hour the cooling bath was removed and the mixture was allowed to warm to room temperature. After a further 1 hour the mixture was poured into brine and extracted with ethyl acetate. The organic layers were dried (MgSO4 ) and concentrated in vacuo to give a yellow oil. Flash column chromatography (elution with 90% hexane, 10% ethyl acetate) gave 1.76 g of the subtitle compound as a pale yellow oil.

Quelle