Sodium Hydroxide → 5-Chloro-3-fluoropyridine-2-carbonyl chloride

Temperature

90 °C

71.38 g of 3-fluoro-5-chloro-2-pyridinecarboxylic acid is initially introduced into a round-bottomed flask and heated up to 90° C. 59 ml of thionyl chloride are added dropwise from a dropping funnel in the course of 30 minutes, and the gas formed is passed into sodium hydroxide solution. The mixture is subsequently stirred at 100° C. for a further 5 hours. The thionyl chloride is then distilled off under normal pressure. After addition of 50 ml of dry toluene, 20 ml thereof are distilled off. The solution thus obtained is poured onto 200 ml of n-hexane and the mixture is stirred overnight. After cooling in an ice-bath, the mixture is filtered and the material on the filter is washed twice with n-hexane. 68.7 9 of the desired compound are obtained as a brown solid.

1. customthe gas formed
2. distillationThe thionyl chloride is then distilled off under normal pressure
3. additionAfter addition of 50 ml of dry toluene, 20 ml
4. distillationthereof are distilled off
5. customThe solution thus obtained
6. stirringthe mixture is stirred overnight
7. temperatureAfter cooling in an ice-bath
8. filtrationthe mixture is filtered
9. washthe material on the filter is washed twice with n-hexane

ORD record

ord-12a1ee2b1c304a3e8e25187ab19d91cc

Source dataset

uspto-grants-2001_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06204221B1