Hydrochloric Acid → Diethyl 2-methyl-3-oxopentanedioate

Temperature

-15 °C

This compound was synthesized according to U.S. Pat. No. 6,833,471. To 20 mL of dry THF that had been purged with Ar(gas) was added diethyl 3-oxopentanedioate (5 mL, 27.54 mmol) and the solution was cooled to −15° C. prior to the dropwise addition of LDA (2M) (15 mL, 30 mmol). The reaction was maintained under Ar(gas) at −15° C., and MeI (3 mL, 48.2 mmol) was added slowly. The reaction was allowed to reach room temperature gradually over 3 hours, and the stirring was continued overnight. After 18 hours, the reaction mixture was poured into 140 mL of a 1:1 mixture of 0.5 N HCl (aq) and Et2O. The organic layer was separated, and the aqueous layer was extracted twice with Et2O (15 mL×2). The organic layers were combined, washed with brine, dried (MgSO4) and concentrated to give an yellow oil, which was flash chromatography purified (SiO2, Hexane:EtOAc=8:2 (v:v)) to afford a colorless/light yellow oil as the title compound. (1.37 g, 23% yield). MW m/z: 215.3 (MW−1, low intensity). 1H NMR (CDCl3, 300 Hz) δ ppm 4.20 (q, 4H), 3.68 (q, 1H), 3.60 (dd, 2H), 1.37 (d, 3H), 1.26 (t, 6H).

1. customThis compound was synthesized
2. customTo 20 mL of dry THF that had been purged with Ar(gas)
3. temperatureThe reaction was maintained under Ar(gas) at −15° C.
4. waitthe stirring was continued overnight
5. waitAfter 18 hours
6. customThe organic layer was separated
7. extractionthe aqueous layer was extracted twice with Et2O (15 mL×2)
8. washwashed with brine
9. dry with materialdried (MgSO4)
10. concentrationconcentrated
11. customto give an yellow oil, which
12. custompurified (SiO2, Hexane:EtOAc=8:2 (v:v))

ORD record

ord-634a69583f6c467da4ed74f4bc49116b

Source dataset

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09095581B2