3-Oxo-azetidine-1-carboxylic acid tert-butyl ester → HCID 122620506, compound

A solution of 5-bromo-2-iodopyrimidine (2 g, 7.02 mmol) in anhydrous toluene (25 mL) was cooled to −78° C. with stirring under nitrogen, forming a thick paste. n-Butyllithium (2.5M solution in hexanes, 2.83 mL) was then added dropwise over 10 minutes. The reaction mixture was stirred at −78° C. for 30 minutes, then solid tert-butyl 3-oxoazetidine-1-carboxylate (1.33 g, 7.74 mmol) was added portionwise. The reaction mixture was allowed to warm to ambient temperature and stirred for 1 h. The reaction mixture was quenched with saturated aqueous ammonium chloride solution (20 mL) and further diluted with water (20 mL). The crude material was extracted into ethyl acetate (2×30 mL). The combined organic phases were dried over sodium sulphate, filtered and concentrated under vacuum. The resulting brown oil (2.66 g) was loaded onto a 50 g KP-silica cartridge, and eluted from a 0-90% ethyl acetate in heptane gradient using a Biotage isolera 4, to afford the title compound (1.083 g, 46%) as a yellow solid. δH (500 MHz, CDCl3) 8.84 (s, 2H), 4.91 (s, 1H), 4.35 (d, J 9.0 Hz, 2H), 4.22 (d, J 9.1 Hz, 2H), 1.48 (s, 9H).

1. customforming a thick paste
2. stirringThe reaction mixture was stirred at −78° C. for 30 minutes
3. stirringstirred for 1 h
4. customThe reaction mixture was quenched with saturated aqueous ammonium chloride solution (20 mL)
5. additionfurther diluted with water (20 mL)
6. extractionThe crude material was extracted into ethyl acetate (2×30 mL)
7. dry with materialThe combined organic phases were dried over sodium sulphate
8. filtrationfiltered
9. concentrationconcentrated under vacuum
10. washeluted from a 0-90% ethyl acetate in heptane gradient

ORD record

ord-ba59485b340e4bb5ab4a1d0052b56411

Source dataset

uspto-grants-2016_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09309243B2