Hydrochloric Acid → 4-Bromoisoquinoline

Temperature

180 °C

The same general procedure set forth in Example 1 above was followed. In a flask equipped with a reflux condenser, dropping funnel, thermometer, and stirrer was placed 33.3 g. (0.20 mole) of isoquinoline hydrochloride, together with 50 ml. of nitrobenzene, and the mixture was stirred and heated to about 180°C. to give a clear yellow solution. To this solution was added dropwise, via the dropping funnel, over a period of 1 hour and 13 minutes, 35.2 g. (0.22 mole) of bromine. The evolution of hydrogen chloride was smooth from the start to the completion of the addition of the bromine. After all the bromine had been added, the reaction mixture was of a single phase, amber red in color. Heating at about 180°C. and stirring were continued after addition of the bromine had been completed. An hour later, a few crystals of a solid material started to collect in the flask near the condenser. After 3 hours and 15 minutes of heating and stirring a very thin slurry of crystals had begun to form and hydrogen chloride evolution had become very slow. After 4 hours and 45 minutes of heating and stirring, the evolution of hydrogen chloride had practically ceased.

1. customIn a flask equipped with a reflux condenser
2. customthermometer, and stirrer was placed
3. customto give a clear yellow solution
4. additionTo this solution was added dropwise, via the dropping funnel, over a period of 1 hour and 13 minutes
5. temperatureHeating at about 180°C.
6. customAn hour
7. customto collect in the flask near the condenser
8. temperature15 minutes of heating
9. stirringstirring a very thin slurry of crystals
10. customto form
11. waitAfter 4 hours
12. temperature45 minutes of heating
13. stirringstirring

ORD record

ord-90f3b3ed3e8142e887d3db126089c6fd

Source dataset

uspto-grants-1976_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US03956301