反应详情

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

1. additionwas added
2. temperaturethe mixture was heated at 60° C. for 40 minutes
3. extractionThe mixture was extracted with ethyl acetate
4. washthe organic layer was washed with brine
5. dry with materialdried over magnesium sulfate
6. concentrationAfter concentrating
7. additiondecaline (100 ml), nitrobenzene (100 ml) and 2 g of Pd-Black were added to the residue
8. temperaturethe mixture was heated at 200° C. overnight in nitrogen stream
9. washThe reaction solution was washed with ethyl acetate
10. extractionextracted with 2N hydrochloric acid
11. washThe aqueous layer was washed with ethyl acetate
12. additionan aqueous sodium hydroxide was added
13. customThe resulting precipitates
14. filtrationwere collected by filtration
15. washwashed with water