Hydrochloric Acid → Ethyl beta-oxopyrazinepropionate

Temperature

-78 °C

To a stirred solution of diethyl malonate (1.25 ml, 1.32 g) in THF (20 ml) under an atmosphere of nitrogen at −60° C. was added nbutyl lithium (2.5 M, 9 ml) dropwise over 15 min, keeping the temperature constant. The reaction became a cloudy white colour from the formation of the di-lithium salt then became yellowish. After 10 min, the reaction was cooled to −78° C., when a solution of pyrazine-2-carbonyl chloride (0.5 g, dark purple solution in THF (10 ml)) was added dropwise over 15 min. The reaction then warmed to −45° C. and stirred for 1 h. The reaction was then poured into 1 M HCl solution (35 ml) with stirring. This was transferred to a separating funnel, and extracted with CH2Cl2 (2×150 ml). The combined organic layers were then washed with sat. NaCO3 soln (1×30 ml) and then dried over MgSO4, filtered and concentrated in vacuo to give the product as a brown oil. Yield 0.65 g, 45%.

1. customThe reaction
2. temperaturethen warmed to −45° C.
3. stirringwith stirring
4. customThis was transferred to a separating funnel
5. extractionextracted with CH2Cl2 (2×150 ml)
6. washThe combined organic layers were then washed with sat. NaCO3 soln (1×30 ml)
7. dry with materialdried over MgSO4
8. filtrationfiltered
9. concentrationconcentrated in vacuo

ORD record

ord-4f7217eedcdf42f292c641e96337a319

Source dataset

uspto-grants-2010_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07816361B2