Potassium Carbonate → Ethyl (4-chloro-2-fluoro-5-hydroxyphenyl)carbamate

The resulting ethyl N-(2-fluoro-4-chloro-5-methoxycarbonyloxyphenyl)carbamate (45.2 g, 155 mmol) was reacted with potassium carbonate (21.4 g, 155 mmol) and water (100 ml) for 2 hours while heating under refluxing. After completion of the reaction, the mixture was cooled to room temperature, the solvent was distilled off under reduced pressure. The residue was made acidic by adding 1N hydrochloric acid (300 ml), and extracted with ethyl acetate (100 ml×3 times). The organic layer was washed with water, dried, the solvent was distilled off under reduced pressure, and the precipitated solid was isolated by filtration. The solid was recrystallized from chloroformhexane to obtain ethyl N-(2-fluoro-4-chloro-5-hydroxyphenyl)carbamate as white crystals (35.2 g, 974 yield).

1. temperaturewhile heating
2. temperatureunder refluxing
3. customAfter completion of the reaction
4. distillationthe solvent was distilled off under reduced pressure
5. additionby adding 1N hydrochloric acid (300 ml)
6. extractionextracted with ethyl acetate (100 ml×3 times)
7. washThe organic layer was washed with water
8. customdried
9. distillationthe solvent was distilled off under reduced pressure
10. customthe precipitated solid was isolated by filtration
11. customThe solid was recrystallized from chloroformhexane
12. customto obtain

ORD record

ord-65aa45fb111f4e59b2e119a77a5adbb6

Source dataset

uspto-grants-1995_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05424277