Acetic Acid → 1-Isopropyl-5,6-Dimethyl-2-oxo-1,2-Dihydropyridine-3-Carbonitrile

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a stirred solution of 2-methyl-3-oxobutanal sodium salt (2.73 g, 22.4 mmol, prepared according to Paine, John B et al., J. Heterocycl. Chem., 1987, 24, 351), 2-cyano-N-isopropylacetamide (2.17 g, 17.2 mmol, prepared according to Wuerthner, Frank et al., J. Amer, Chem. Soc., 2002, 32, 9431) in N,N-dimethylformamide (17.2 mL) were added piperidine (292 mg, 3.43 mmol) and acetic acid (1.34 g, 22.4 mmol) successively at room temperature, and the mixture was stirred at 135° C. for 7 h. After cooling, the mixture was quenched with water (100 mL), extracted with dichloromethane (50 mL×4). The combined organic layers were dried over magnesium sulfate and concentrated in vacuo. The residue was chromatographed on a column of silica gel eluting with n-hexane/ethyl acetate (v/v=2/1˜1/1) to give 840 mg (26%) of the title compound as an orange colored solid.

Herkunft & Nachweise