1,3-Propanediamine, N'-(ethylcarbonimidoyl)-N,N-dimethyl-, monohydrochloride → 3-[4-(2-Chloroethyl)phenyl]-5,7-dimethyl-2-[2-(1,3-thiazol-2-yl)ethyl]-3H-imidazo[4,5-b]pyridine

Participants

Reaction Steps

To a mixture of N2-[4-(2-chloroethyl)phenyl]-4,6-dimethyl-2,3-pyridinediamine (step 2, 276 mg, 1.0 mmol) and 3-(1,3-thiazol-2-yl)propanoic acid (157 mg, 1.0 mmol) in dichloromethane (10 mL) was added 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, hydrochloride (WSC) (192 mg, 1.0 mmol) in one portion. The reaction mixture was stirred overnight at room temperature. The reaction mixture was concentrated under reduced pressure. The residue was suspended in toluene (20 mL) and heated at 150° C. for 5 h. The reaction mixture was poured into water (50 mL), the organic phase was separated, and the aqueous phase was extracted with ethyl acetate (100 mL). The combined organic phases were washed with brine (50 mL) and dried (Na2SO4). After removal of solvent, the crude product was purified by flash column chromatography on silica gel eluting with hexane/ethyl acetate (1:1) to afford 210 mg (53%) of the title compound: MS (EI) m/z 396 (M+); 1H-NMR (CDCl3) δ 7.63 (1H, d, J=3.4 Hz), 7.39 (2H, d, J=8.3 Hz), 7.28 (2H, d, J=8.3 Hz), 7.15 (1H, d, J=3.4 Hz), 6.93 (1H, s), 3.78 (2H, t, J=7.4 Hz), 3.69-3.50 (2H, m), 3.39-3.20 (2H, m), 3.15 (2H, t, J=7.4 Hz), 2.66 (3H, s), 2.53 (3H, s).

Provenance & Evidence