Dimethyl Sulfoxide → 3-Oxo-azetidine-1-carboxylic acid tert-butyl ester

Temperature

-78 °C

A mixture of oxalyl chloride (2.78 ml, 31.8 mmol) in CH2Cl2 (80 ml) in a 500 ml round-bottomed flask was cooled to −78° C., and DMSO (4.51 ml, 63.5 mmol) was added dropwise to the mixture over 15 min. The reaction mixture was then stirred at the same temperature for 15 min. A solution of tert-butyl 3-hydroxyazetidine-1-carboxylate (5 g, 28.9 mmol) in CH2Cl2 (50 ml) followed by a solution triethylamine (16.09 ml, 115 mmol) in CH2Cl2 (70 ml) were added dropwise to the reaction mixture. The reaction mixture was warmed to room temperature, and then stirred overnight. The reaction mixture was washed with brine, and the aqueous layer back extracted with CH2Cl2 (200 ml). The combined organic layers were washed with water, dried over Na2SO4, filtered and concentrated in vacuum to provide a crude mixture. The crude product was then purified by column chromatography (15% EtOAc in Hexane) to afford tert-butyl 3-oxoazetidine-1-carboxylate Yield: 4 g (81%). 1H NMR (400 MHz, CDCl3): δ 4.69 (s, 4H), 1.49 (s, 9H).

1. additionwere added dropwise to the reaction mixture
2. temperatureThe reaction mixture was warmed to room temperature
3. stirringstirred overnight
4. washThe reaction mixture was washed with brine
5. extractionthe aqueous layer back extracted with CH2Cl2 (200 ml)
6. washThe combined organic layers were washed with water
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated in vacuum
10. customto provide a crude mixture
11. customThe crude product was then purified by column chromatography (15% EtOAc in Hexane)

ORD record

ord-23c89a3eb79c461da1a03c065f4af5c4

Source dataset

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09096580B2