Ethyl isobutyrate → Ethyl 2,2-dimethylpent-4-ynoate

Temperature

0 °C

Diisopropylamine (45.9 mL, 0.33 mol) was dissolved in THF (300 mL) and cooled to 0° C. under N2. n-Butyllithium (131.0 mL, 0.33 mol) was added dropwise over 30 minutes, the mixture was stirred at 0° C. for an additional 30 minutes, and then cooled to −78° C. Ethyl isobutyrate (40 mL, 0.30 mol) was added dropwise in THF (30 mL) and the mixture was stirred at −78° C. for 1 hour. Propargyl bromide (36.4 mL, 0.33 mol) was added dropwise in HMPA (60 mL). The mixture was stirred at −78° C. for 1 hour and then quenched with saturated NH4Cl solution and warmed to room temperature. THF was removed in vacuo, and the residue was dissolved in ether and washed four times with water. The organic layer was dried over MgSO4, filtered, and concentrated. The crude material was distilled under reduced pressure (˜29 inHg, bp 68-70° C.) to obtain the desired product.

1. temperaturecooled to −78° C
2. stirringthe mixture was stirred at −78° C. for 1 hour
3. stirringThe mixture was stirred at −78° C. for 1 hour
4. customquenched with saturated NH4Cl solution
5. temperaturewarmed to room temperature
6. customTHF was removed in vacuo
7. dissolutionthe residue was dissolved in ether
8. washwashed four times with water
9. dry with materialThe organic layer was dried over MgSO4
10. filtrationfiltered
11. concentrationconcentrated
12. distillationThe crude material was distilled under reduced pressure (˜29 inHg, bp 68-70° C.)

ORD record

ord-217e7986ab564cdab624fc66cd10d1b0

Source dataset

uspto-grants-2008_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07405302B2