Diisopropylethylamine → 4-benzyl-7-((4-(4-chlorophenyl)-5,6-dihydropyridin-1(2H)-yl)methyl)-3,4-dihydropyrido[2,3-b]pyrazin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

4-benzyl-7-(hydroxymethyl)-3,4-dihydropyrido[2,3-b]pyrazin-2(1H)-one (100 mg, 0.37 mmol) was suspended in propionitrile (1 mL) and (cyanomethyl)trimethylphosphonium iodide (123.0 mg, 0.51 mmol) was added followed by N-ethyl-N-isopropylpropan-2-amine (180 ul, 1.03 mmol). To the stirred mixture was then added 4-(4-chlorophenyl)-1,2,3,6-tetrahydropyridine hydrochloride (104.5 mg, 0.45 mmol). The reaction was heated to 90° C. with stirring for 2 h. The reaction was then cooled to room temperature and diluted with water (3 mL) and filtered. The solids were collected and refluxed in ethanol (5 mL) for 1 h. The suspension was cooled back to room temperature and filtered. The precipitate was filtered off and dried in vacuum to afford the title compound (45.3 mg, 27%) as a white solid. 1H NMR (DMSO-d6) δ (ppm): 10.57 (s, 1H), 7.66 (d, J=2.0 Hz, 1H), 7.41-7.48 (m, 2H), 7.23-7.41 (m, 7H), 7.03 (d, J=2.0 Hz, 1H), 6.19 (s, 1H), 4.72 (s, 2H), 3.86 (s, 2H), 3.43 (s, 2H), 3.03 (d, J=2.8 Hz, 2H), 2.58-2.65 (m, 2H), 2.44 (br. s., 2H). [M+H] calc'd for C, 26; H, 25; ClN, 4; O, 445; found, 445.

Provenance & Evidence