Hexane → 5,5-Diethoxy-3-pentyn-2-one

Temperature

-70 °C

Propargylaldehyde diethylacetal (40 g, 312 mmol) was dissolved in THF (200 mL) under argon and cooled to −70° C. Then a 1.6 M solution of n-butyllithium in hexane (234 mL, 374 mmol) was added and stirring continued for 30 min at −30° C. Then N-methoxy-N-methylacetamide (38.6 g, 374 mmol) in THF (10 mL) was added. After 30 min at −30° C., the reaction was quenched by addition of saturated NH4Cl solution (20 mL). The product was extracted with AcOEt (2×200 mL), saturated solution of NH4Cl (2×200 mL), dried and concentrated. Chromatography on silica gel with a heptane/ethyl acetate gradient 100:0 to 95:5 gave 38.5 g (72%) of a colorless oil. GC/MS: m/z=232(M).

1. waitAfter 30 min at −30° C.
2. customthe reaction was quenched by addition of saturated NH4Cl solution (20 mL)
3. extractionThe product was extracted with AcOEt (2×200 mL), saturated solution of NH4Cl (2×200 mL)
4. customdried
5. concentrationconcentrated

ORD record

ord-b7fd59d23f69456ba6e179d4b83fbda9

Source dataset

uspto-grants-2008_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07351700B2