Ammonia → 1,2,3,4-Tetrahydro-7-nitroisoquinoline

Participants

Reaction Conditions

Reaction Steps

1,2,3,4-Tetrahydroisoquinoline (50 g; 1 equiv.) was added at 0° C., in the course of 90 minutes, to 185 ml of sulfuric acid, and the reaction mixture was stirred for 30 minutes at 0° C. Potassium nitrate (40.7 g; 1.2 equiv.) was then added in portions, and stirring was carried out for 15 hours at room temperature. When the conversion was complete, the reaction mixture was shaken on 500 g of ice and adjusted to pH 8-9 with ammonia solution. Extraction with chloroform was then carried out 3 times, and the combined organic phases were dried over sodium sulfate and concentrated under reduced pressure. The residue was taken up in IPA (500 ml) and cooled to 0° C., and hydrochloric acid (2 equiv.) was added. The resulting solid was filtered out and recrystallised from methanol. 7-Nitro-1,2,3,4-tetrahydroisoquinoline (35 g; 52.3%) was obtained in the form of a white solid.

Provenance & Evidence