Hydrochloric Acid → 6-Bromo-4-cinnolinol

Temperatur

0 °C

A solution of Example 34B (6.28 g, 24.4 mmol) in THF (75 mL) was treated with concentrated HCl (aq.) (15 mL) and water (15 mL), heated to reflux for 1 hour, and concentrated to remove the THF. The aqueous solution was treated with additional water (5 mL) and concentrated HCl (5 mL), cooled to 0° C., treated with a solution of NaNO2 (1.85 g, 26.84 mmol) in water (10 mL) in 5 portions, warmed to room temperature gradually over a 2-hour period, and stirred overnight at room temperature. The reaction was heated to reflux for 6 hours, and filtered. The solid was washed with water (50 mL) and diethyl ether (50 mL) and dried under vacuum to provide the desired product (3.0 g, 54%).

1. temperatureheated
2. temperatureto reflux for 1 hour
3. concentrationconcentrated
4. customto remove the THF
5. additionThe aqueous solution was treated with additional water (5 mL) and concentrated HCl (5 mL)
6. temperaturewarmed to room temperature gradually over a 2-hour period
7. temperatureThe reaction was heated
8. temperatureto reflux for 6 hours
9. filtrationfiltered
10. washThe solid was washed with water (50 mL) and diethyl ether (50 mL)
11. customdried under vacuum

ORD-Eintrag

ord-e28fb059d7274dd78d539cae589bcf11

Quelldatensatz

uspto-grants-2004_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06831175B2