Perchloric Acid → HCID 178489025, compound

Participants

Reaction Steps

To a clear light yellow solution of 2-fluoro-4-methoxybenzaldehyde (802 mg, 5.2 mmol) and 5-amino-1H-pyrazole-4-carbonitrile (562 mg, 5.2 mmol) in methanol (20 mL) were added a neat cyclopentyl isonitrile (500 mg, 5.2 mmol) and perchloric acid (104 mg, 93.3 μL, 1.04 mmol) at RT under nitrogen atmosphere. Lots of brown solids were precipitated within 1 h and the resulting suspension was stirred for 15 h. After 15 h, it became a dark brown solution without any solids. Then, the solvent was removed under vacuum and the residue was purified using an ISCO (120 g) column chromatography eluting with 0-50% EA in hexanes. The desired fractions were combined and the solvent was removed under vacuum to obtain 203 mg (11.5% yield) of 3-(cyclopentylamino)-2-(2-fluoro-4-methoxyphenyl)-1H-imidazo[1,2-b]pyrazole-7-carbonitrile as an yellow solid. LC/MS calcd. for C18H18FN5O (m/e) 339.37, obsd. 340.2 (M+H, ES+).

Provenance & Evidence