2-Methyl-6,7,8-trimethoxy-1[4,5,6-triethoxy-7-nitro-3-phthalidyl]-1,2,3,4-tetrahydro-isoquinoline → 458L

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Reaction Steps

270 g of the nitro derivative (a) is added to 1.570 liters of ethanol and 21 g of Raney nickel in an autoclave. Hydrogen is added under a pressure of 10 atmospheres and the reactants are heated at a temperature of 65° while stirring. After 1 hour 45 minutes the theoretical volume of hydrogen has been absorbed. The solution is cooled and filtered. The ethanol is distilled in vacuo, the residue is dissolved in 0.6 l of methanol, 60 g of potassium hydroxide tablets are added, and the mixture is heated under reflux for 1 hour while stirring. The mixture is cooled and allowed to crystallise. 194.5 g (yield=76%) of 2-methyl-6,7,8-trimethoxy-1-(4,5,6-triethoxy-7-amino-3-phthalidyl)-1,2,3,4-tetrahydro-isoquinoline is obtained in the form of white crystals having a melting point of 144° and exhibiting only a single spot when analysed by thin layer chromatography.

Provenance & Evidence