Dimethylformamide → HCID 58826433, compound

To a stirred, cooled (0° C.) solution of (1R,3S,4S)-3-azido-4-hydroxy-cyclopentanecarboxylic acid methyl ester (300 mg; CAS 213742-85-9) in DMF (5 ml) under an argon atmosphere was added NaH (78 mg; 55% dispersion in mineral oil). The ice bath was removed and stirring at r.t. was continued for 1 h. The mixture was cooled again and methyl iodide (0.3 ml) was added in one portion. The mixture (slowly warming up to r.t.) was then stirred for 18 h. More methyl iodide (0.3 ml) was added and the mixture (orange slurry) was stirred at r.t. for another 7 h. More methyl iodide (0.3 ml) was added and stirring was continued for another 17 h. The mixture was diluted with EtOAc and washed with H2O (10 ml). The aqueous phase was back extracted with EtOAc. The combined organics were washed with H2O and brine, dried (MgSO4), filtered and concentrated. The crude product was purified by column chromatography (silica gel; gradient: cyclohexane→cyclohexane/EtOAc 65:35) to give (3S,4S)-3-azido-4-methoxy-cyclopentanecarboxylic acid methyl ester (215 mg, epimeric mixture) as light yellow oil. MS: 200.3 ([M+H]+).

1. customThe ice bath was removed
2. temperatureThe mixture was cooled again
3. additionmethyl iodide (0.3 ml) was added in one portion
4. temperatureThe mixture (slowly warming up to r.t.)
5. stirringwas then stirred for 18 h
6. additionMore methyl iodide (0.3 ml) was added
7. stirringthe mixture (orange slurry) was stirred at r.t. for another 7 h
8. additionMore methyl iodide (0.3 ml) was added
9. stirringstirring
10. waitwas continued for another 17 h
11. additionThe mixture was diluted with EtOAc
12. washwashed with H2O (10 ml)
13. extractionThe aqueous phase was back extracted with EtOAc
14. washThe combined organics were washed with H2O and brine
15. dry with materialdried (MgSO4)
16. filtrationfiltered
17. concentrationconcentrated
18. customThe crude product was purified by column chromatography (silica gel; gradient: cyclohexane→cyclohexane/EtOAc 65:35)

ORD record

ord-57b0b01c07f248aaaffb524c2f9a4cd9

Source dataset

uspto-grants-2010_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07678917B2