Ethyl propiolate → HCID 18358858, compound

Temperature

-70 °C

To a solution of ethyl propiolate (4.05 mL, 40 mmol) in tetrahydrofuran (125 mL) at −78° C. under nitrogen was added n-BuLi (2.5 mL, 40 mmol, 1.6 M in hexane). The reaction mixture was stirred at about −70° C. for 0.5 hours and then 2-nitro-5-chlorobenzaldehyde (6.75 g, 36.4 mmol) was added dropwise. The reaction mixture was stirred at 78° C. for 0.25 hours, warmed to −60° C., quenched with acetic acid (5 mL) and then warmed to room temperature. The reaction mixture was partitioned between ether (250 mL) and water (250 mL). The layers were separated and the organic layer was washed with brine (250 mL) and dried over Na2SO4. The mixture was filtered and the filtrate was concentrated in vacuo. The residue was purified by flash chromatography eluting with hexane/ethyl acetate (4:1) to afford 6.12 g (59%) of the title compound as a yellow oil which solidified on standing.

1. stirringThe reaction mixture was stirred at 78° C. for 0.25 hours
2. temperaturewarmed to −60° C.
3. customquenched with acetic acid (5 mL)
4. temperaturewarmed to room temperature
5. customThe reaction mixture was partitioned between ether (250 mL) and water (250 mL)
6. customThe layers were separated
7. washthe organic layer was washed with brine (250 mL)
8. dry with materialdried over Na2SO4
9. filtrationThe mixture was filtered
10. concentrationthe filtrate was concentrated in vacuo
11. customThe residue was purified by flash chromatography
12. washeluting with hexane/ethyl acetate (4:1)

ORD record

ord-8c4113f3a39f49efbf948886008554b8

Source dataset

uspto-grants-2001_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06313290B1