Hydrochloric Acid → 4-Tert-butyl-2-fluoroaniline

Temperatur

90 °C

To 303 g of 4-t-butyl-2-fluoro-N-methoxycarbonylaniline as the crude product was added 657 g of a 30% aqueous sodium hydroxide solution. The mixture was heated under reflux at a temperature around 90° C. for 4 hr and was allowed to cool. Water (1,000 mL) was then added thereto, and the mixture was extracted four times with 500 mL of hexane. The organic layers thus obtained were combined, and 2 M hydrochloric acid was added thereto, followed by vigorous stirring to convert the amino group to a hydrochloride form. Subsequently, an aqueous layer was separated and was adjusted to pH 9 by the addition of aqueous sodium hydroxide solution to bring the amino group to a free form. Extraction was carried out twice with 1,000 mL of toluene. The organic layers thus obtained were combined, and the combined organic layer was washed with saturated brine. The solvent was then removed from the organic layer by distillation to give 92.9 g of 4-t-butyl-2-fluoroaniline as an oily substantially single product (yield 65.6% (yield in two steps of t-butylation-deprotection)).

1. temperatureThe mixture was heated
2. temperatureto cool
3. extractionthe mixture was extracted four times with 500 mL of hexane
4. customThe organic layers thus obtained
5. customSubsequently, an aqueous layer was separated
6. additionwas adjusted to pH 9 by the addition of aqueous sodium hydroxide solution
7. extractionExtraction
8. customThe organic layers thus obtained
9. washthe combined organic layer was washed with saturated brine
10. customThe solvent was then removed from the organic layer by distillation

ORD-Eintrag

ord-fca4ca2ce3ac4fab93ef9e70d7e7c30b

Quelldatensatz

uspto-grants-2008_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07439382B2