Potassium Nitrate → 4-Bromo-5-nitroisoquinoline

Potassium nitrate (5.34 g; 0.052 mol) was added to 20 ml of concentrated sulfuric acid and slowly dissolved by careful heating. The resulting solution was added dropwise to a solution of 4-bromoisoquinoline (10 g; 0.048 mol) dissolved in 40 ml of the same acid at 0° C. After removal of the cooling bath, the solution was stirred for one hour at room temperature. The reaction mixture was then poured onto crushed ice (400 g) and made basic with ammonium hydroxide. The resulting yellow precipitate was collected by filtration and the filtrate was extracted with diethyl ether (3×500 ml), dried (Na2SO4), and concentrated to give a yellow solid that was combined with the initial precipitate. Recrystallization from methanol gave 12.1 g (89%) of slightly yellow crystals: mp 172-174° C.; 1H NMR: (300 MHz, CDCl3): 9.27 (s, 1H); 8.87 (s, 1H); 8.21 (dd, 1H, J=6.6, 1.2 Hz); 7.96 (dd, 1H, J=6.6, 1.2 Hz); 7.73 (t, 1H, J=7.5 Hz). CIMS m/z: 253 (M+H+, 100%); 255 (M+H++2, 100%). Anal. Calc'd for C9H5BrN2O2: C, 42.72; H, 1.99; N, 11.07. Found: C, 42.59; H, 1.76; N, 10.87.

1. dissolutionslowly dissolved by careful heating
2. customAfter removal of the cooling bath
3. additionThe reaction mixture was then poured
4. customonto crushed ice (400 g)
5. filtrationThe resulting yellow precipitate was collected by filtration
6. extractionthe filtrate was extracted with diethyl ether (3×500 ml)
7. dry with materialdried (Na2SO4)
8. concentrationconcentrated
9. customto give a yellow solid
10. customRecrystallization from methanol
11. customgave 12.1 g (89%) of slightly yellow crystals

ORDレコード

ord-68c9a267a5804a6f93542e368854c222

出典データセット

uspto-grants-2005_07

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US06916823B2