Acetic Anhydride → 5,6,13,13a-tetrahydro-2,3,11-trimethoxy-10-acetoxy-8H-dibenzo [a,g]quinolizine

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Reaction Steps

0.8 g. of 10-hydroxy-2,3,11-trimethoxy-5,6,13,13a-tetrahydro-8H-dibenzo[a, g]quinolizine was dissolved in 8 ml of anhydrous pyridine. To the resulting solution 2 ml of acetic anhydride was added dropwise with stirring, while cooling in an ice-bath. After the mixture was stirred at room temperature for 5 hours, the excessive acetic anhydride was distilled off under reduced pressure, and the residue obtained was extracted with chloroform. The chloroform layer was washed with a 1N-sodium hydroxide solution and then with water, dried over potassium carbonate and evaporated to dryness. Recrystallization of the residue from ethanol-petroleum ether afforded 0.3 g. (33.3% yield) of 5,6,13,13a-tetrahydro-2,3,11-trimethoxy-10-acetoxy-8H-dibenzo [a,g]quinolizine as colorless needles having a melting point of 162° to 164°C.

Provenance & Evidence