Chloroacetaldehyde → Methyl imidazo(1,2-a)pyridine-7-carboxylate

関与物質

反応手順

To a solution of Methyl 2-aminopyridine-4-carboxylate (10.0 g, 66 mmol, 1.0 equiv) in EtOH (150 ml) was added NaHCO3 (11.1 g, 132 mmol, 2.0 equiv) followed by chloroacetaldehyde (13.0 ml, 99 mmol, 1.5 equiv). The mixture was refluxed for 2 h. Solvents were removed under reduced pressure and the crude mixture was partitioned between water and EtOAc. The resulting precipitate was washed with Et2O and recrystallised from MeOH/Et2O to afford 8.4 g of product. 1H NMR (400 MHz, DMSO-d6): 8.66 (1H, d), 8.16 (2H, s), 7.80 (1H, s), 7.33 (1H, d), 3.90 (3H, s). MS: [M+H]+ 177.

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