Ammonia → 7-Nitroisoquinoline

To concentrated sulfuric acid (70 ml) was added 15 g of potassium nitrate, followed by adding a solution of 18 g (0.14 mol) of 3,4-dihydroisoquinoline in concentrated sulfuric acid (70 ml) at −15 degrees over 20 minutes. After stirring at room temperature for 1 hour, the mixture was heated at 60 degrees for 40 minutes. The reaction mixture was poured onto ice water, and the mixture was basified with aqueous ammonia and extracted with ethyl acetate. The organic layer was washed with brine, dried over magnesium sulfate and concentrated. To the residue were added decalin (100 ml), nitrobenzene (100 ml) and Pd-Black (2 g), followed by heating at 200 degrees in a stream of nitrogen overnight. The reaction mixture was washed with ethyl acetate and extracted with 2 N hydrochloric acid. The aqueous layer was washed with ethyl acetate, followed by adding an aqueous sodium hydroxide. The resulting precipitates were collected by filtration and washed with water, to give 14.4 g of the title compound.

1. temperaturethe mixture was heated at 60 degrees for 40 minutes
2. additionThe reaction mixture was poured onto ice water
3. extractionextracted with ethyl acetate
4. washThe organic layer was washed with brine
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated
7. additionTo the residue were added decalin (100 ml), nitrobenzene (100 ml) and Pd-Black (2 g)
8. temperatureby heating at 200 degrees in a stream of nitrogen overnight
9. washThe reaction mixture was washed with ethyl acetate
10. extractionextracted with 2 N hydrochloric acid
11. washThe aqueous layer was washed with ethyl acetate
12. additionby adding an aqueous sodium hydroxide
13. customThe resulting precipitates
14. filtrationwere collected by filtration
15. washwashed with water

ORD record

ord-3c7446512e6b489ebf0818172a385e8d

Source dataset

uspto-grants-2004_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06787534B2