Acetic Anhydride → 1-(6-Hydroxy-3,4-dihydroisoquinolin-2(1H)-yl)ethan-1-one

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Reaction Steps

5.0 g of 6-hydroxy-1,2,3,4-tetrahydroisoquinoline are converted into the bisacetyl compound using acetic anhydride or acetyl chloride/triethylamine, and, without purification, this compound is heated under reflux for 6 hours with 10 ml of diethylamine in 50 ml of ethanol. The mixture is evaporated in vacuo in a rotary evaporator, and the residue is chromatographed on silica gel using ethyl acetate/methanol in the ratio 9:1. A yellow oil which crystallizes on trituration with diethyl ether is obtained. Yield: 5.2 g (78% of theory), melting point: 129°-130°.

Provenance & Evidence