7-Methyl-6-nitro-imidazo[1,2-a]pyridine-2-carboxylic acid ethyl ester synthesis

Yield:132272-53-8 68%

Reaction Conditions:

with Sodium hydrogenocarbonate in 1,4-dioxane at 100; for 16 h;

Steps:

102 Example 102: SN40070 Ethyl 7-Methyl-6-((3-methyl-2-oxo-1-(tetrahydro-2H-pyran- 4-yl)-2,3-dihydro-1H-imidazo[4,5-c]pyridin-6-yl)amino)imidazo[1,2-a]pyridine-3- carboxylate (129)

. Ethyl 7-Methyl-6-nitroimidazo[1,2-a]pyridine-2-carboxylate. Ethyl bromopyruvate (1.90 g, 9.80 mmol) in dioxane (2 mL) was added to a stirred suspension of 4-methyl-5-nitropyridin- 2-amine (1.0 g, 6.53 mmol) and NaHCO3 (1.1 g, 13.1 mmol) in dioxane (25 mL) at 20 °C. The mixture was stirred at 100 °C for 16 h. The solvent was evaporated. The residue was suspended in water (100 mL) filtered and washed with pet. ether and dried to give ester (1.10 g, 68%) as a tan powder: mp (water) 160-162 °C; 1H NMR [(CD3)2SO] δ 9.71 (s, 1 H, H-5), 8.64 (d, J = 0.6 Hz, 1 H, H-3), 7.67 (d, J = 0.9 Hz, 1 H, H-8), 4.33 (q, J = 7.1 Hz, 2 H, CH2O), 2.39 (d, J = 0.9 Hz, 3 H, 7-CH3), 1.33 (t, J = 7.1 Hz, 3 H, CH3); MS m/z 250.1 (MH+, 100%); HRMS calcd for C11H12N3O4 (MH+) m/z 250.0822, found 250.0818 (1.8 ppm).

References:

WO2022/64430,2022,A1 Location in patent:Page/Page column 131; 132