Bromine → HCID 15085720, compound

Temperature

0 °C

Ethyl 3-fluoro-2,2-dimethyl-3-butenoate (14 g) and bromine (11 g) were dissolved in 50 mL of CCl4, and the solution heated at reflux for one hour. The solution was then cooled and concentrated in vacuo. The dibromo ester was taken up in 100 mL of dry THF and stirred at 0° C. while DBU (13 g) was added dropwise. Stirring was continued overnight, allowing the solution to warm to ambient temperature. The dark solution was then poured onto ice and excess 10N HCl, and the product was isolated by extraction into ether, washing with a saturated brine solution, drying and removal of the solvent. The bromovinyl ester (10.4 g) was then hydrolyzed by treatment with 7.3 g of potassium hydroxide in a solution of 10 mL of ethanol and 90 mL of water, at the reflux temperature for one hour. After the solution had cooled, it was diluted with 100 mL of water, acidified, extracted with ether (2×100 mL), and the combined organic layer washed with brine, dried and concentrated to yield 7.3 g of (Z) 4-bromo-3-fluoro-2,2-dimethyl-3-butenoic acid as an oil.

1. temperaturethe solution heated
2. temperatureat reflux for one hour
3. temperatureThe solution was then cooled
4. concentrationconcentrated in vacuo
5. additionwas added dropwise
6. stirringStirring
7. temperatureto warm to ambient temperature
8. additionThe dark solution was then poured onto ice and excess 10N HCl
9. customthe product was isolated by extraction into ether
10. washwashing with a saturated brine solution
11. customdrying
12. customremoval of the solvent
13. waithydrolyzed by treatment with 7.3 g of potassium hydroxide in a solution of 10 mL of ethanol and 90 mL of water, at the reflux temperature for one hour
14. temperatureAfter the solution had cooled
15. additionit was diluted with 100 mL of water
16. extractionextracted with ether (2×100 mL)
17. washthe combined organic layer washed with brine
18. customdried
19. concentrationconcentrated

ORD record

ord-edaae982fd6d46ac8aa8d1d4b52da26a

Source dataset

uspto-grants-1990_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04944795