Potassium Carbonate → 6-Bromo-2-(trimethylsilyl)pyrazolo[1,5-a]pyrazine

Participants

Reaction Conditions

Reaction Steps

O-(Mesitylenesulfonyl)hydroxylamine (680 mg, 3.2 mmol) was added in one portion to a stirred solution of 2-bromo-5-trimethylsilanylethynyl-pyrazine (Step 1, 3 mmol) in CH2Cl2 (3 ml) at 0° C. The mixture was stirred at 0° C. for 30 minutes, at RT for 4 hours, then evaporated. The N-amino adduct was used without further manipulation. K2CO3 (410 mg, 3 mmol) was added to a stirred solution of the N-aminopyrazine from above in dry DMF (5 ml) at RT under nitrogen. After 6 hours the mixture was partitioned between EtOAc/H2O. The organic layer was washed with brine (×2), then evaporated. The residue was taken up in CH2Cl2 and passed through a phase separating cartridge. The filtrate was evaporated and the residue was purified by chromatography on silica (2→4% EtOAc/Petrol) to give the title compound (62 mg, oil) MS: [M+H]+ 270/272.

Provenance & Evidence