Ammonium Chloride → Tert-butyl 3-(4-bromo-1,3-thiazol-2-yl)-3-hydroxyazetidine-1-carboxylate

Temperature

-78 °C

n-Butyllithium (1.6 M in THF, 6.3 mL, 10.1 mmol) was added dropwise to a −78° C. solution of 2,4-dibromothiazole (2.00 g, 8.30 mmol) in tetrahydrofuran (50 mL), and the mixture stirred at −78° C. for 1 h. A solution of tert-butyl 3-oxoazetidine-1-carboxylate (2.83 g, 16.55 mmol) in tetrahydrofuran (5 mL) was added, and the resulting mixture stirred for 1 h at room temperature. The reaction mixture was poured into saturated aqueous ammonium chloride solution (50 mL) and extracted with dichloromethane (3×50 mL). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The residue was purified via column chromatography on silica gel (eluting with 20% with ethyl acetate/petroleum ether) to afford tert-butyl 3-(4-bromothiazol-2-yl)-3-hydroxyazetidine-1-carboxylate (0.890 g, 32%) as a white solid. MS (ESI, pos. ion) m/z 335, 337 [M+H]+.

1. stirringthe resulting mixture stirred for 1 h at room temperature
2. extractionextracted with dichloromethane (3×50 mL)
3. dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated under vacuum
6. customThe residue was purified via column chromatography on silica gel (eluting with 20% with ethyl acetate/petroleum ether)

ORD record

ord-3766589eb33a4a8aad5f5869d9ff37d3

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09388161B2