Triphenylphosphine → tert-Butyl 4-(acetylthio)piperidine-1-carboxylate

Temperature

-78 °C

Triphenylphosphine (7.37 g) and Intermediate 11 (4.71 g) were dissolved in tetrahydrofuran (40 ml), under a nitrogen atmosphere, and cooled to −78° C. Diethyl azodicarboxylate (4.42 ml) was added via syringe, followed by thiolacetic acid (2.17 ml). The reaction was then stirred for 18 h, slowly warming to room temperature. The reaction was reduced in vacuo and the residue redissolved in ethyl acetate (150 ml) and washed with saturated sodium bicarbonate solution (3×20 ml), water (2×20 ml) and saturated brine (20 ml). The organic phase was then dried (Na2SO4), and diluted with hexane (150-200 ml). The resultant precipitate was removed by filtration, and the filtrate evaporated under reduced pressure. The pale green residue was then purified by silica gel column chromatography with 1% methanol in dichloromethane as eluent to yield the title compound as a colourless oil (0.99 g, 16%).

1. temperatureslowly warming to room temperature
2. washwashed with saturated sodium bicarbonate solution (3×20 ml), water (2×20 ml) and saturated brine (20 ml)
3. dry with materialThe organic phase was then dried (Na2SO4)
4. additiondiluted with hexane (150-200 ml)
5. customThe resultant precipitate was removed by filtration
6. customthe filtrate evaporated under reduced pressure
7. customThe pale green residue was then purified by silica gel column chromatography with 1% methanol in dichloromethane as eluent

ORD record

ord-1cba8281e3c24d57aa93560ea09f57a2

Source dataset

uspto-grants-2004_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06680338B2