反应详情

A solution of sodium hydroxide (4.38 g, 109.4 mmol) in 70 ml of water was added to a solution of 6,7-dimethoxy-3-isoquinolinecarboxylic acid, methyl ester (22.54 g, 91.2 mmol) in 1800 ml of water:tetrahydrofuran 1:1. After stirring overnight at room temperature, the tetrahydrofuran was distilled off in vacuo and the pH of the remaining aqueous solution was brought to 3 with 3N hydrochloric acid. The resulting precipitate was filtered off with suction, washed with water and dried in vacuo. Yield: 19.57 g; melting point 228.2° C.

1. distillationthe tetrahydrofuran was distilled off in vacuo
2. filtrationThe resulting precipitate was filtered off with suction
3. washwashed with water
4. customdried in vacuo