Reaction #2267064

Reaction equation

6,7-Dimethoxy-1-methyl-3,4-dihydroxyisoquinoline

formic acid-triethylamine

sodium carbonate

→

(S)-6,7-dimethoxy-1-methyl-1,2,3,4-tetrahydroisoquinoline

Yield 99.0%

Solvents

acetonitrile

Conditions

Workup

1. 1
   Extractionto extract the product in ethyl acetate
2. 2
   OtherAfter evaporation of the solvent, 1H-NMR(CDCl3) of the resulting product
3. 3
   OtherThen, the product was purified by silica gel chromatography

Procedure

6,7-Dimethoxy-1-methyl-3,4-dihydroxyisoquinoline (Table 6-2a) (1.03 g, 5 mmol) and a ruthenium catalyst (Table 7) (R, R)-1a (16 mg, 0.025 mmol) were dissolved in acetonitrile (10 ml), followed by addition of a mixture of formic acid-triethylamine (5:2), for agitation at 28° C. for 3 hours. To the reaction mixture was added an aqueous sodium carbonate solution to extract the product in ethyl acetate. After evaporation of the solvent, 1H-NMR(CDCl3) of the resulting product was measured to calculate the conversion. Then, the product was purified by silica gel chromatography, to determine the optical purity and absolute configuration of the resulting optically active amine by HPLC or GLC. As collectively shown in Table 8, (S)-6,7-dimethoxy-1-methyl-1,2,3,4-tetrahydroisoquinoline (1.02 g, yield of 99%, 96% ee) was obtained.

Source