Triethylamine → Tert-butyl cyclopropyl(3-formyl-6-((trimethylsilyl)ethynyl)imidazo[1,2-a]pyrazin-8-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

Triethylamine (912 μL, 6.56 mmol) was added to tert-butyl 6-bromo-3-formylimidazo[1,2-a]pyrazine-8-yl(cyclopropyl)carbamate (250 mg, 0.66 mmol) dissolved in anhydrous DMF (2.2 mL) in a 15 mL pressure tube. The solution was degassed with a stream of N2 for 10 min. Trimethylsilylacetylene (927 μL, 6.56 mmol), Pd(PPh3)4 (76 mg, 0.07 mmol), and copper(I) iodide (25 mg, 0.13 mmol) were added and the reaction was sealed and heated to 65° C. for 24 h. The reaction was diluted with EtOAc (50 mL) and then washed with 10% brine (4×50 mL) and brine (50 mL). The organics were dried over MgSO4, filtered and concentrated in vacuo. The residue was purified via flash column chromatography (30% EtOAc/hexanes) to give tert-butyl cyclopropyl(3-formyl-6-((trimethylsilyl)ethynyl)imidazo[1,2-a]pyrazin-8-yl)carbamate (186 mg, 71%) as a brown foamy solid. LCMS (ES): >95% pure, m/z 400 [M+1]+.

Provenance & Evidence