Acetone → 4-Methyl-2-oxo-6-propyl-1,2-dihydro-3-pyridinecarbonitrile

Participants

Reaction Steps

To a solution of NaNH2 (32.5 g, 862 mmol) in anhydrous ether (500 mL) at 30° C. was added dropwise a mixture of butyric acid ethyl ester (50 g, 431 mmol) and acetone (37.5 g, 646.5 mol). After addition, the reaction mixture was stirred for 4 h. The reaction mixture was poured onto ice water with stirring. Additional ether was added, and the layers were separated. The aqueous layer was acidified to pH 5.0 with 2 N HCl and then to pH 7.5 with Na2CO3. The aqueous layer was then extracted with ether. The combined organic layers were dried over Na2SO4, filtered, and concentrated in vacuo. The crude product, 2,4-heptanedione (20 g, 156 mmol), and 2-cyanoacetamide (13.12 g, 156 mmol) were suspended in EtOH (160 mL) at 75° C., followed by addition of piperidine (13.2 g, 156 mmol). The contents were stirred and heated at reflux for 1 h. The mixture was cooled to room temperature and filtered. The collected solid was suspended in water and stirred for 1 h. The mixture was filtered and dried to give 4-methyl-2-oxo-6-propyl-1,2-dihydro-3-pyridinecarbonitrile (11 g, 40%). LCMS E-S (M+H)=181.1. 1H NMR (400 MHz, DMSO-d6) δ ppm 12.3-12.4 (br s, 1H), 6.25 (s, 1H), 3.64 (s, 3H), 2.50 (t, 2H), 1.63 (m, 2H), 0.94 (t, 3H).

Provenance & Evidence