Propanal → HCID 22004561, compound

Participants

Reaction Steps

Tert-butyl hydroperoxide (70%, 1.0 ml, 7.25 mmol) and a solution of FeSO4.7H2O (3.02 g, 10.9 mmol) in water (8 ml) were added concurrently to a solution of methyl-2-pyrazine carboxylate (250 mg, 1.81 mmol) and propionaldehyde (0.78 ml, 0.9 mmol) in H2SO4 (0.75 ml) at 0 C. The reaction was allowed to warm to room temperature and was stirred for 2 hours. Solid Na2S2O5 was added (until starch/iodide test negative) and the mixture extracted with dichloromethane. Concentration in vacuo and flash column chromatography over silica gel in ethyl acetate:hexane (15:85) yielded methyl-5-propionyl-2-pyrazinecarboxylate as a pale yellow solid (106 mg). The methyl ester was treated with LiOH (25 mg, 0.6 mmol) in tetrahydrofuran (15 ml) and water (0.5 ml). After 2 hours at room temperature the mixture was acidified with HCl (2N). Work-up followed by concentration of the organic phase in vacuo gave the title compound (92 mg).

Provenance & Evidence