Formaldehyde → Dimethyl 4-(2,6-dichlorophenyl)-6-(2-phenylethyl)-2-(1-oxo-1-methoxy-2-propen-2-yl)-1,4-dihydropyridine-3,5-dicarboxylate

Participants

Reaction Steps

Dimethyl 4-(2,6-dichlorophenyl)-2-methoxycarbonylmethyl-6-[2-(phenyl)ethyl]-1,4-dihydropyridine-3,5-dicarboxylate (588 mg, 1.135 m mol) and N-methylpiperazine (0.132 ml, 1.19 m mol) were dissolved in acetic acid (3 ml) and to the solution was added paraformaldehyde. The mixture was stirred at room temperature overnight. The mixture was concentrated in vacuo and partitioned between CH2Cl2 (50 ml) and aqueous NaHCO3 solution (20 ml). The aqueous layer was extracted with CH2Cl2 (30 ml). The combined organic layer and the extract were washed with brine (10 ml), dried (MgSO4), and concentrated in vacuo to give a yellow oil. This was crystallized from ethyl acetate and isopropyl ether gave a yellow solid (270 mg, 50.9%). Second crop was obtained from the mother liquid (78 mg, 14.7%). 1H NMR (D2O) δ7.35-7.16 (m, 7H), 7-05-6.97 (m, 1H), 6.21 (br.s, 1H), 6.06 (s, 1H), 5.52 (br.s, 1H), 5.43 (br.s, 1H), 3.73 (s, 3H), 3.57 (s, 3H), 3.46 (s, 3H), 3.10-2.80 (m, 4H).

Provenance & Evidence