反应详情

温度

-10 °C

To a solution of isopropylmagnesium chloride lithium chloride complex (1.56 mL of a 1.3M solution in THF, 2.02 mmol) in dry THF (5 mL) at −15° C. under an atmosphere of nitrogen was introduced 2-bromo-5-methyl-1,3,4-oxadiazole (300 mg, 1.84 mmol). The reaction mixture was warmed to −10° C. for 30 minutes. A solution of 4-(trimethylsilyl)but-3-yn-2-one (0.37 ml, 2.21 mmol) in dry THF (5 mL) was added and the reaction mixture warmed to 0° C. for 1 hr. After further warming to RT for 30 minutes, the solution was cooled to 0° C. and saturated aqueous ammonium chloride (5 mL) introduced. The reaction mixture was extracted with DCM (3×10 mL extractions) and the combined organic extracts were dried (Na2SO4), filtered and concentrated in vacuo. Purification of the residue by flash chromatography (Biotage, heptane/EtOAc followed by an EtOAc/MeOH gradient) furnished the title compound as an orange oil: 1H NMR (500 MHz, CDCl3) delta 0.18 (9H, s), 1.95 (3H, s), 2.57 (3H, s), 3.13 (1H, s); LC-MS: m/z=+224.95 (M+H)+.

1. temperaturethe reaction mixture warmed to 0° C. for 1 hr
2. temperatureAfter further warming to RT for 30 minutes
3. temperaturethe solution was cooled to 0° C.
4. extractionThe reaction mixture was extracted with DCM (3×10 mL extractions)
5. dry with materialthe combined organic extracts were dried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customPurification of the residue by flash chromatography (Biotage, heptane/EtOAc