((1,1-Dimethyl-2-propynyl)oxy)trimethylsilane → 4-Methyl-1-(pyridin-4-yl)-4-(trimethylsilyloxy)pent-2-yn-1-one

Temperature

-78 °C

To a stirred solution of trimethyl(2-methylbut-3-yn-2-yloxy)silane (4.22 g, 25.4 mmol) in dry THF (100 mL) was added n-BuLi (17.9 mL, 28.7 mmol, 1.6 M in hexane) dropwise at −78° C. under an inert atmosphere for a period of 10 min. After being stirred for 30 min at −78° C., a solution of N-methoxy-N-methylisonicotinamide (5.0 g, 31.8 mmol) in dry THF (15 mL) was added to reaction mixture and stirring was continued for an additional 2 h at −78° C. The reaction mixture was quenched with a saturated NH4Cl solution and extracted with EtOAc (2×100 mL). The combined organic layers were washed with water (80 mL), brine (50 mL), dried over Na2SO4, filtered and concentrated in vacuo to obtain the crude product. The crude material was purified via silica gel column chromatography eluting with 2-3% EtOAc in Hexane to afford 4-methyl-1-(pyridin-4-yl)-4-(trimethylsilyloxy)pent-2-yn-1-one (4.8 g, 57%) as an oil.

1. stirringstirring
2. waitwas continued for an additional 2 h at −78° C
3. customThe reaction mixture was quenched with a saturated NH4Cl solution
4. extractionextracted with EtOAc (2×100 mL)
5. washThe combined organic layers were washed with water (80 mL), brine (50 mL)
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customto obtain the crude product
10. customThe crude material was purified via silica gel column chromatography
11. washeluting with 2-3% EtOAc in Hexane

ORD record

ord-4f23d672e6704843924853289a57922e

Source dataset

uspto-grants-2011_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08071595B2