Reaktion #52776

Reaktionsgleichung

4-(2-morpholin-4-ylcyclohex-1-enyl)-4-oxo-butyric acid ethyl ester

diethyl aminomalonate hydrochloride

sodium acetate

acetic acid

→

3-(2-ethoxycarbonylethyl)-4,5,6,7-tetrahydro-1H-indole-2-carboxylic acid ethyl ester

Ausbeute 109.6%

Lösungsmittel

ethyl acetate

Water

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe ethyl acetate layer was separated
2. 2
   Waschenwashed three times with brine
3. 3
   TrocknenThe solution was dried over anhydrous sodium sulfate
4. 4
   Sonstigethe ethyl acetate was removed
5. 5
   Sonstigea rotary evaporator

Vorschrift

Crude 4-(2-morpholin-4-ylcyclohex-1-enyl)-4-oxo-butyric acid ethyl ester (454 g), 398 g of diethyl aminomalonate hydrochloride, 162 g of sodium acetate and 350 mL of glacial acetic acid were heated to 108° C. over 30 minutes. The mixture was held at 100-108° C. for 2 hours and then cooled to about 50° C. in a water bath. Water (2500 mL) and 700 mL of ethyl acetate were added. The ethyl acetate layer was separated and washed three times with brine, twice with saturated sodium bicarbonate solution and once with brine. The solution was dried over anhydrous sodium sulfate, and the ethyl acetate was removed using a rotary evaporator to give 494 g (105% yield) of crude 3-(2-ethoxycarbonylethyl)-4,5,6,7-tetrahydro-1H-indole-2-carboxylic acid ethyl ester as an oil. The crude mixture was chromatographed on a silica gel column using a 1:10 mixture of ethyl acetate:hexane as the eluent to give 122.1 g of pure 3-(2-ethoxycarbonylethyl)-4,5,6,7-tetrahydro-1H-indole-2-carboxylic acid ethyl ester as a low melting solid.

Quelle