4-Bromo-3-methyl-1H-pyrazole

white to cream-colored powder

A mixture of K2C03 (858 mg, 6.21 mmol), To a solution of A mixture of 2-(4-bromo-3-methyl-pyrazol- 1 -yl)-2-methyl- cyclopentanone and 2-(4-bromo-5-methyl-pyrazol-i -yl)-2- methyl-cyclopentanone (160 mg, 622.26 tmol), NH2l3oc (437 mg, 3.73 mmol), t-l3uONa (120 mg, 1.24 mmol) and [2-(2-aminoethyl)phenyl]-chioro-palladium;ditert-butyl-[2- (2, 4, 6-triisopropylphenyl)phenyl]phosphane (107 mg, 155. 57 tmol) in THF (2 mE) was degassed and purged with N2 for 3 times, and then the mixture was stirred at 90 C. for 2 h under N2. The reaction mixture was filtered and the filtrate was concentrated under reduced pressure. The residue was purified by prep-HPEC (neutral) to give tert-butyl N-[5- methyl-i -(1 -methyl-2-oxo-cyclopentyl)pyrazol-4-yl]car- bamate and tert-butyl N-[5-methyl- 1 -(1 -methyl-2-oxo-cy- clopentyl)pyrazol-4-yl]carbamate as a yellow gum. ECMS:RT 1.203 mi mlz=294.3 [M+H]; a mixture of 2-(4-bromo-3-methyl-pyrazol-i -yl)cyclopentanone and 2-(4-bromo-5- methyl-pyrazol-i -yl)cyclopentanone (6.5 g, 26.74 mmol) in THF (30 mE) was added EiHMDS (1 M, 34.76 mE) and stirred at -78C. for 1 h. Mel (4.93 g, 34.76 mmol, 2.16 mE) was then added at -78 C. and stirred at 15 C. for 15 h. The reaction mixture was quenched by addition of saturated aq. NH4C1 (200 mE) at 0 C., and then extracted with EtOAc (3x70 mE). The combined organic layers were washed with brine (100 mE), dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (PE:EtOAc=4: ito 2:1) to give the mixture of 2-(4-bromo-3-methyl-pyrazol-i -yl)-2- methyl-cyclopentanone) and2-(4-bromo-5-methyl-pyrazol- 1 -yl)-2-methyl-cyclopentanone as a yellow gum. ECMS: RT0.747 mi mlz=257.i [M+H]; 2-(4-bromo-3-methylpyrazol-1-yl)cyclopentanone and 2-(4-bromo-5-methylpyrazol-1-yl)cyclopentanone: To a solution of

Molecular Weight:161.00
XLogP3:1.3
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:1
Exact Mass:159.96361
Monoisotopic Mass:159.96361
Topological Polar Surface Area:28.7
Heavy Atom Count:7
Complexity:66.7
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes