Methanol → Pyrrolo[1,2-a]pyrimidine

Participants

Reaction Steps

A mixture of methyl 5-nitro-4-quinolin-4-yl-1H-pyrrole-2-carboxylate (23, 90 mg, 0.3 mmol), Pd/C (5%, 45 mg), and MeOH (15 mL) was stirred under argon for 5 min, then under hydrogen for 40 min before removal of the catalyst by filtration through celite. To the orange color filtrate was added 2-(4-methoxyphenyl)malondialdehyde (54 mg, 0.3 mmol) followed by AcOH (2 mL). The resulting reaction mixture was stirred overnight at 82° C., then cooled to rt, quenched with sat. NaHCO3, and extracted with ethyl acetate and CH2Cl2. The combined organic layers were dried over Na2SO4, filtered, and concentrated. The residue was purified by column chromatography on silica gel using CH2Cl2/MeOH (90:10) to give 25 as a yellow solid (90 mg, 73%). 1H NMR (DMSO-d6, 500 MHz) δ 9.80 (d, J=3.0 Hz, 1H), 8.97 (d, J=5.0 Hz, 1H), 8.87 (d, J=3.0 Hz, 1H), 8.10 (m, 1H), 8.04 (s, 1H), 7.80 (m, 1H), 7.75 (d, J=5.0 Hz, 1H), 7.75 (d, J=8.5 Hz, 2H), 7.61 (m, 1H), 7.15 (d, J=8.5 Hz, 2H), 3.94 (s, 3H), 3.84 (s, 3H); mp 230-231° C.

Provenance & Evidence