4-Bromopyrazole → Ethyl 2-[(4-bromo-1H-pyrazol-1-yl)methyl]cyclopropanecarboxylate

HRID 2266700Notes

Reaction equation

CS(O[CH2:6][CH:7]1[CH2:9][CH:8]1[C:10]([O:12][CH2:13][CH3:14])=[O:11])(=O)=O.[Br:15][C:16]1[CH:17]=[N:18][NH:19][CH:20]=1.[H-].[Na+]>CN(C=O)C>[Br:15][C:16]1[CH:17]=[N:18][N:19]([CH2:6][CH:7]2[CH2:9][CH:8]2[C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH:20]=1

Participants

Conditions

Temperature: 90 °C

Procedure

A reaction mixture of ethyl 2-{[(methylsulfonyl)oxy]methyl}cyclopropanecarboxylate (880 mg; 4.0 mmol), 4-bromopyrazole (4-2, 588 mg, 4.0 mmol) and NaH 60% in mineral oil (240 mg, 6.0 mmol) with 3.0 mL of DMF was formed. The resulting mixture was stirred at 90° C. under N2 for four hours. The reaction mixture was partitioned between EtOAc (200 mL) and saturated NaHCO3 solution (2×50 mL); brine (50 mL). The organic layer was dried (Na2SO4), then concentrated by vacuum to afford 812 mg of (4-3) as a yellow oil (74%). 1H NMR (400 MHz, chloroform-D) δ ppm 0.85 (dd, J=7.96, 3.16 Hz, 1H) 0.88-0.98 (m, 1H) 1.18-1.29 (m, 3H) 1.56-1.71 (m, 1H) 1.79-1.94 (m, 1H) 3.96-4.08 (m, 2H) 4.07-4.17 (m, 2H) 7.45 (d, J=3.79 Hz, 2H). LCMS calcd for C10H13BrN2O2 (M+H) 274, found 274. HPLC purity 95%.

Workup

customwas formed
customThe reaction mixture was partitioned between EtOAc (200 mL) and saturated NaHCO3 solution (2×50 mL)
dry with materialThe organic layer was dried (Na2SO4)
concentrationconcentrated by vacuum

Sources & evidence

ORD record: ord-740f535f233d461ea8d4603ead0d3bca
Source dataset: uspto-grants-2010_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07858643B2

Reaction notes

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