Triethylamine → Phenyl 2-[4-(2-ethyl-5,7-dimethyl-3H-imidazo[4,5-b]pyridin-3-yl)phenyl]ethylcarbamate

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Reaction Steps

To a stirred solution of 2-[4-(2-ethyl-5,7-dimethyl-3H-imidazo[4,5-b]pyridin-3-yl)phenyl]ethylamine (step 9 of Example 1, 1.55 g, 5.3 mmol) and triethylamine (0.80 mL, 5.8 mmol) in dichloromethane (26 mL) cooled in an ice bath was added dropwise phenyl chloroformate (0.69 mL, 5.5 mmol), and the mixture was stirred at ambient temperature. After 30 min, the reaction mixture was partitioned between saturated aqueous sodium bicarbonate (30 mL) and dichloromethane (30 mL). The organic layer was separated and the aqueous phase was extracted with dichloromethane (30 mL). The combined organic phases were dried (Na2SO4) and concentrated under reduced pressure. The residue was recrystallized from dichloromethane/hexane to give 1.90 g (87%) of the title compound as pale brown crystals: 1H-NMR (CDCl3) δ 7.43-7.11 (9H, m), 6.91 (1H, s), 5.50 (1H, br.s), 3.57 (2H, pseudo q, J=6.9 Hz), 2.98 (2H, t, J=6.9 Hz), 2.83 (2H, q, J=7.6 Hz), 2.66 (3H, s), 2.52 (3H, s), 1.28 (3H, t, J=7.6 Hz).

Provenance & Evidence