反应详情

Heating 3,4-dihydro-3-methyl-8-phenylisocoumarin and benzylamine hydrobromide in benzylamine at 160° C. gives N-benzyl-6-(2-hydroxy-2-methylethyl)2-biphenylcarboxamide which is converted to the corresponding mesylate and then cyclized to 2-benzyl-3,4-dihydro-3-methyl-8-phenyl-1(2H)-isoquinolone with sodium hydride. This compound is then reduced with lithium aluminum hydride to give 2-benzyl-3-methyl-8-phenyl-1,2,3,4-tetrahydroisoquinoline. Hydrogenation of this product using 5% palladium-on-carbon on the catalyst affords 3-methyl-8-phenyl-1,2,3,4-tetrahydroisoquinoline. Reacting 3-methyl-8-1,2,3,4-tetrahydroisoquinoline with formaldehyde and formic acid affords 2,3-dimethyl-8-phenyl-1,2,3,4-tetrahydroisoquinoline.