Dimethyl Sulfoxide → tert-butyl N-(2-methyl-4-oxobutan-2-yl)carbamate

Temperatur

-78 °C

DMSO (1.22 mL, 17.2 mmol) was added to a solution of oxalyl chloride (1.1 mL, 12.9 mmol) at -78° C. in dichloromethane (15 mL). The mixture was stirred for 15 min at -78° C. A solution of 3-hydroxy-1,1-dimethylpropylcarbamic acid tert-butyl ester (1.75 g, 8.6 mmol) in dichloromethane (10 mL) was added dropwise over a period of 15 min. The solution was stirred at -78° C. for another 15 min. Triethylamine (6.0 mL, 43 mmol) was added. The solution was stirred at -78° C. for 5 min and then warmed to room temperature. The solution was diluted with dichloromethane (100 mL) and extracted with 1 N hydrochloric acid (100 mL). The aqueous phase was extracted with dichloromethane (50 mL). The combined organic layers were washed with saturated sodium hydrogen carbonate solution (100 mL) and dried over magnesium sulfate. The solvent was removed in vacuo. The crude product was purified by column chromatography on silica (140 g) with ethyl acetate/heptane (1:3) to give 1.10 g of 3-(tert-butoxycarbonylamino)-3-methylbutanal.

1. stirringThe solution was stirred at -78° C. for another 15 min
2. stirringThe solution was stirred at -78° C. for 5 min
3. temperaturewarmed to room temperature
4. extractionextracted with 1 N hydrochloric acid (100 mL)
5. extractionThe aqueous phase was extracted with dichloromethane (50 mL)
6. washThe combined organic layers were washed with saturated sodium hydrogen carbonate solution (100 mL)
7. dry with materialdried over magnesium sulfate
8. customThe solvent was removed in vacuo
9. customThe crude product was purified by column chromatography on silica (140 g) with ethyl acetate/heptane (1:3)

ORD-Eintrag

ord-7b5e16c2efda4a3f8a9fafb042d66f68

Quelldatensatz

uspto-grants-2000_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06127341