N,N-Dipropylethylamine → N-(2-methyl-5-(5-(3-oxocyclobutyl)-1,2,4-oxadiazol-3-yl)phenyl)imidazo[1,2-a]pyridine-3-carboxamide

Participants

Reaction Conditions

Reaction Steps

HATU (1.41 g, 3.72 mmol) was added in one portion to a stirred solution of 3-oxocyclobutanecarboxylic acid (0.405 g, 3.55 mmol) and Pr2NEt (0.62 mL, 3.7 mmol) in dry DMF (5 mL). After 10 minutes, N-(5-(N′-hydroxycarbamimidoyl)-2-methylphenyl)imidazo[1,2-a]pyridine-3-carboxamide (9) (1.0 g, 3.23 mmol) was added in one portion and continued to stir for another 30 minutes. The resulting solution was heated (110° C.) for 30 minutes and then cooled to room temperature. The solvent was evaporated and the residue was partitioned with saturated NH4Cl and EtOAc. The organic layer was dried with MgSO4 and filtered. The residue was purified on silica gel using 10% MeOH in dichloromethane to obtain N-(2-methyl-5-(5-(3-oxocyclobutyl)-1,2,4-oxadiazol-3-yl)phenyl)imidazo[1,2-a]pyridine-3-carboxamide (10). 1H NMR (400 MHz, d6-DMSO) δ 10.20 (s, 1 H), 9.53-9.51 (m, 1 H), 8.71 (s, 1 H), 8.08 (d, J=1.6 Hz, 1 H), 7.91-7.88 (m, 1 H), 7.85 (dd, J=2.0, 8.0 Hz, 1 H), 7.72-7.68 (m, 1 H), 7.51 (d, J=8.4 Hz, 1 H), 7.34-7.30 (m, 1 H), 4.12-4.04 (m, 1 H), 3.70-3.53 (m, 4 H), 2.37 (s, 3 H). MS m/z 388.1 (M+1)+.

Provenance & Evidence