Formamide → 3,4-Dihydro-6-methoxy-5-(phenylmethoxy)-2(1H)-isoquinolinecarboxaldehyde

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Reaction Steps

122.3 g of 5-benzyloxy-1,2,3,4-tetrahydro-6-methoxy-isoquinoline-hydrochloride, 140 ml of formic acid, and 700 ml of formamide are heated for 2.5 hours under reflux. The mixture is then poured over 2 kg of ice and extracted with methylene chloride. After evaporation to dryness of the methylene chloride solution under reduced pressure, the residue is recrystallized from methanol-water. 102.3 g of 5-benzyloxy-2-formyl-1,2,3,4-tetrahydro-6-methoxy-isoquinoline are obtained. m.p. = 117.5° - 118.5° C.

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