Hexane → 5,5-Diethoxy-1,1,1-trifluoro-pent-3-yn-2-one

Temperature

-70 °C

3,3-Diethoxy-1-propyne (10 mL, 70 mmol) was dissolved under argon in THF (200 mL) and cooled to −70° C. Then a 1.6 M solution of n-butyllithium in hexane (48 mL, 77 mmol) was added slowly at −70° C., then allowed to warm to −30° C. and stirred at −30° C. for 30 min, then cooled again to −70° C. Ethyl trifluoroacetate (9.2 mL, 77 mmol) was added in one portion at −70° C. (the temperature rose to −50°) then stirred without cooling until −30° C. was reached, then quenched with sat. NH4Cl solution (20 mL). Extraction: 2×AcOEt, 1× sat. NH4Cl sat., 1× sat. NaCl. Chromatography on silica gel in heptane/ethyl acetate 5:1 afforded 4.94 g (31%) of an orange oil. GC/MS: m/z=223 (M−H).

1. temperatureto warm to −30° C.
2. temperaturecooled again to −70° C
3. customrose to −50°
4. stirringthen stirred
5. temperaturewithout cooling until −30° C.
6. customquenched with sat. NH4Cl solution (20 mL)
7. extractionExtraction

ORD record

ord-bd8bfa233bfc4de1a697db5f004574ee

Source dataset

uspto-grants-2008_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07351700B2