Water → t-butyl pyruvate

Temperature

-20 °C

tert-Butyl 2-methyl-1,3-dithiane-2-carboxylate (2 g, 8.547 mmol) was dissolved in acetone (85.5 mL), and water (0.5 mL) was added. The flask was then cooled in a cold bath at −20° C. Small aliquots of N-bromosuceinimide (15.4 g, 85.47 mmol) were added over 20 minutes. The reaction mixture was stirred at the same temperature for further 30 minutes, and then quenched by adding an aqueous solution of sodium bicarbonate (7.18 g, 85.47 mmol in 90 mL of water). Insoluble material was removed by filtration. The filtrate was diluted in water (200 mL) and extracted with tert-butyl methyl ether (150 mL). The separated organic layer was washed with water and a saturated brine in order, then dried over anhydrous sodium sulfate, and then filtered. The filtrate was concentrated. The residue was purified by silica gel column chromatography (n-hexane/ethyl acetate) to obtain the target compound as pale yellow oil at a yield of 40%.

1. additionSmall aliquots of N-bromosuceinimide (15.4 g, 85.47 mmol) were added over 20 minutes
2. customquenched
3. customInsoluble material was removed by filtration
4. additionThe filtrate was diluted in water (200 mL)
5. extractionextracted with tert-butyl methyl ether (150 mL)
6. washThe separated organic layer was washed with water
7. dry with materiala saturated brine in order, then dried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationThe filtrate was concentrated
10. customThe residue was purified by silica gel column chromatography (n-hexane/ethyl acetate)

ORD record

ord-fc5da3aab26e492e8d81de3a8079b2c7

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09266853B2