3-Hydroxyquinoline → 2-Bromoquinolin-3-ol

Temperatur

-5 °C

6.0 mg (41 mmol) of 3-hydroxyquinoline are dissolved in 50 ml of 10% strength sodium hydroxide solution, giving a yellowish brown color. The reaction mixture is cooled to -5° C. using an ice/common salt mixture. A mixture comprising 6.6 g (2.1 ml, 41 mmol) of bromine dissolved in 50 ml of 10% strength sodium hydroxide solution is added dropwise to this solution over a period of 1 hour. During this the temperature of the reaction solution must never exceed 0° C. After this time, the cooling is removed and the reaction solution is stirred at room temperature for another 3 hours. The reaction solution is then cooled to -10° C. The reaction solution cooled to -10° C. [sic]. The reaction solution is then brought to a pH of 3 with 2N hydrochloric acid, during which the temperature of the reaction solution must never exceed -5° to 0° C. This gives the crude product as a light yellow solid. The crude product is recrystallized from 180 ml of ethyl acetate.

1. customgiving a yellowish brown color
2. additionis added dropwise to this solution over a period of 1 hour
3. customnever exceed 0° C
4. customAfter this time, the cooling is removed
5. temperatureThe reaction solution is then cooled to -10° C
6. temperatureThe reaction solution cooled to -10° C. [sic]
7. customnever exceed -5° to 0° C

ORD-Eintrag

ord-c0d2322f3d3a49da8ecf7609cbfaa5c3

Quelldatensatz

uspto-grants-1993_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05266700