4-Fluorophenylboronic acid → 6-(4-Fluoro-phenyl)-pyrazolo[1,5-a]pyrazine

HRID 341235Notes

Reaction equation

Br[C:2]1[N:3]=[CH:4][C:5]2[N:6]([N:8]=[C:9]([Si](C)(C)C)[CH:10]=2)[CH:7]=1.[F:15][C:16]1[CH:21]=[CH:20][C:19](B(O)O)=[CH:18][CH:17]=1>CC#N.C([O-])([O-])=O.[Na+].[Na+]>[F:15][C:16]1[CH:21]=[CH:20][C:19]([C:2]2[N:3]=[CH:4][C:5]3[N:6]([N:8]=[CH:9][CH:10]=3)[CH:7]=2)=[CH:18][CH:17]=1

Participants

Conditions

Temperature: 150 °C

Procedure

A mixture of 6-bromo-2-trimethylsilanyl-pyrazolo[1,5-a]pyrazine (60 mg, 0.23 mmol), 4-fluorophenylboronic acid (40 mg, 0.29 mmol) and PdCl2dppf (10 mg, 0.014 mmol) in CH3CN (1 ml) and 2N Na2CO3 (aq, 1 ml) in a microwave vial was deoxygenated by bubbling N2 through for 20 seconds. The vial was sealed and then stirred and heated at 150° C. in the microwave for 20 minutes. After cooling the reaction mixture was partitioned between CH2Cl2/H2O. The mixture was passed through a phase separating cartridge. The organic layer was evaporated and the residue was purified by chromatography on silica (5→20% EtOAc/Petrol) to give the title compound (14 mg, oil) 1H NMR (400 MHz, CDCl3): 9.15 (1H, d), 8.75 (1H, s), 8.06 (1H, d), 7.98-7.92 (2H, m), 7.24-7.14 (2H, m), 6.84 (1H, d).

Workup

customwas deoxygenated
customby bubbling N2 through for 20 seconds
customThe vial was sealed
temperatureAfter cooling the reaction mixture
customwas partitioned between CH2Cl2/H2O
customseparating cartridge
customThe organic layer was evaporated
customthe residue was purified by chromatography on silica (5→20% EtOAc/Petrol)

Sources & evidence

ORD record: ord-7fd67825ba4e401988498a87d14e97ff
Source dataset: uspto-grants-2014_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08895745B2

Reaction notes

Loading…