Ethyl fluoroacetate → N-t-butyl-3-(fluoroacetyl)-2-thiophenesulfonamide

Temperatur

-78 °C

2.98 g (0.0mole) of N-t-butyl-3-bromo-2-thiophenesulfonamide was dissolved in 50mi of dry tetrahydrofuran and the mixture was cooled to -78° C. under nitrogen gas. To the reaction solution was slowly added dropwise 8.4 ml of n-butyl lithium (2.5N) and then the temperature of the mixture was raised slowly to -20° C. and again cooled to -78° C. 1.2 g (0.011 mole) of ethyl fluoroacetate was added slowly to the reaction mixture. The temperature of the mixture was raised again slowly to -20° C. and then the mixture was stirred for 10 minutes. To the reaction mixture was added 100 ml of 5% aqueous ammonium chloride solution, and then added 100 ml of ethylacetate to separate the organic layer. The extracted organic layer was dried over anhydrous magnesium sulfate and concentrated. The residue was subjeced to column chromatography on silica gel to obtain 2.0 g (Yield: 72%) of the pure title compound as a liquid.

1. temperaturethe temperature of the mixture was raised slowly to -20° C.
2. temperatureagain cooled to -78° C
3. temperatureThe temperature of the mixture was raised again slowly to -20° C.
4. customto separate the organic layer
5. dry with materialThe extracted organic layer was dried over anhydrous magnesium sulfate
6. concentrationconcentrated

ORD-Eintrag

ord-c8e3bb374a104faca742086988b3b35f

Quelldatensatz

uspto-grants-1998_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05726127