Dimethyl Sulfoxide → Ethyl (3R,4R,5S)-4-acetamido-5-azido-3-(1-ethylpropoxy)-1-cyclohexene-1-carboxylate

Temperature

87.5 °C

To a solution of 340 mg of 22, 1.2 mL of DMSO and 1.2 mL of EtOH in a 5.0 mL round-bottom flask equipped with a magnetic stirrer, a reflux condenser and an inert gas supply was added 113 mg of sodium azide and the reaction mixture was stirred for 21 h at 85-90° C. The brown reaction mixture was cooled to RT, treated with 7.0 mL of a aqueous 1 M NaHCO3 and extracted with 7.0 mL tert-butyl methyl ether. The organic phase was dried with (Na2SO4), filtered and evaporated at 40° C./250-10 mbar to afford 280 mg of the crude product as brown crystals. The crude product was dissolved in 3.0 mL of tert-butyl methyl ether and stirred for 16 h at −20° C. which resulted in the formation of a beige suspension. The suspension was filtered over a pre cooled (−20° C.) glass filter frit and washed with 1.5 mL of pre cooled (−20° C.) tert-butyl methyl ether. The white crystals were dried at 40° C./10 mbar for 2 h to afford 60 mg of 24 as white crystals

1. temperatureThe brown reaction mixture was cooled to RT
2. extractionextracted with 7.0 mL tert-butyl methyl ether
3. dry with materialThe organic phase was dried with (Na2SO4)
4. filtrationfiltered
5. customevaporated at 40° C./250-10 mbar
6. customto afford 280 mg of the crude product as brown crystals
7. stirringstirred for 16 h at −20° C. which
8. customresulted in the formation of a beige suspension
9. filtrationThe suspension was filtered over a pre
10. temperaturecooled (−20° C.) glass
11. filtrationfilter frit
12. washwashed with 1.5 mL of pre
13. temperaturecooled (−20° C.) tert-butyl methyl ether
14. customThe white crystals were dried at 40° C./10 mbar for 2 h

ORD record

ord-82a8cfbf375a43cea8cb3e0ed446d6af

Source dataset

uspto-grants-2009_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07531687B2