Pyridine → (Z)-1,2,3,4-tetrahydro-6,7-dimethoxy-2-(3,4,5-trimethoxybenzoyl)-1-[(3,4-dimethoxyphenyl)methylene]isoquinoline

Participants

Reaction Steps

A suspension of 6 parts of 3,4-dihydro-6,7-dimethoxy-1-[(3,4-dimethoxyphenyl)methylene]isoquinoline and 6 parts of 3,4,5-trimethoxybenzoyl chloride in 50 parts of pyridine is heated at the boiling point under reflux in a nitrogen atmosphere for 45 minutes, whereupon 180 parts of chloroform is introduced. The resultant solution is washed with water, dried over anhydrous sodium sulfate, and stripped of solvent by vacuum distillation. The residue is taken up in benzene; and the benzene solution is chromatographed on silica gel, using benzene and mixtures thereof with increasing amounts of ethyl acetate as developing solvents. From an eluate comprising 30% ethyl acetate in benzene, on evaporation of solvent, (Z)-1,2,3,4-tetrahydro-6,7-dimethoxy-2-(3,4,5-trimethoxybenzoyl)-1-[(3,4-dimethoxyphenyl)methylene]isoquinoline melting at 195°-200° is obtained as the residue.

Provenance & Evidence