Diisopropylethylamine → Ethyl 5-(4-(but-3-en-1-yl)-4-methylpiperidin-1-yl)-6-(2-methoxy-2-oxoacetyl)-7-methylimidazo[1,2-a]pyridine-2-carboxylate

Participants

Reaction Steps

A solution of ethyl 5-chloro-6-(2-methoxy-2-oxoacetyl)-7-methylimidazo[1,2-a]pyridine-2-carboxylate (0.40 g, 1.23 mmol, 1 equiv), DIPEA (0.52 mL, 2.96 mmol, 2.4 equiv), and 4-(but-3-en-1-yl)-4-methylpiperidine, HCl (0.23 g, 1.23 mmol, 1 equiv). After 2 h, the reaction was added to saturated aqueous NaHCO3 and extracted with EtOAc (×3). The combined EtOAc extracts were dried (Na2SO4) and concentrated in vacuo. The crude product was purified by flash column chromatography (0-100% EtOAc/hex) to provide the product (0.44, 81%) as a viscous yellow oil that slowly crystallized. 1H NMR (400 MHz, CDCl3) δ 8.28-8.13 (m, 1H), 7.37 (br. s., 1H), 5.96-5.78 (m, 1H), 5.08 (d, J=17.6 Hz, 1H), 5.00 (d, J=10.5 Hz, 1H), 4.57-4.43 (m, 2H), 3.97 (s, 3H), 3.62-3.28 (m, 2H), 3.01-2.87 (m, 2H), 2.34 (d, J=0.8 Hz, 3H), 2.14-2.04 (m, 2H), 1.62-1.38 (m, 9H), 1.14-0.99 (m, 3H); LCMS (ESI, M+1): 442.25.

Provenance & Evidence