Water → 4-Bromo-3-phenyl-1-trityl-1H-pyrazole

HRID 1624603Notes

Reaction equation

[Br:1][C:2]1[C:3]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)=[N:4][NH:5][CH:6]=1.[C:13](Cl)([C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)([C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.C([O-])([O-])=O.[K+].[K+].O>CN(C=O)C>[Br:1][C:2]1[C:3]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)=[N:4][N:5]([C:13]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)([C:26]2[CH:27]=[CH:28][CH:29]=[CH:30][CH:31]=2)[C:20]2[CH:21]=[CH:22][CH:23]=[CH:24][CH:25]=2)[CH:6]=1

Participants

Conditions

Temperature: 90 °C

Procedure

A suspension of 4-bromo-3-phenyl-1H-pyrazole (6.13 g, 27.5 mmol), trityl chloride (15.3 g, 55.0 mmol), and K2CO3 (11.4 g, 82.5 mmol) in DMF (100 mL) was stirred for 60 h at 90° C. After cooling to room temperature, the reaction mixture was poured into water and extracted with AcOEt. The extract was washed with water and brine, dried over MgSO4, concentrated under reduced pressure. The residue was recrystallized from hexane/THF to give the title compound (8.00 g, 63% yield) as a white solid: mp 181-183° C.; 1H NMR (300 MHz, CDCl3): δ ppm 7.16-7.22 (6H, m), 7.28-7.41 (13H, m), 7.87-7.91 (2H, m). Anal. Calcd for C28H21BrN2: C, 72.26; H, 4.55; N, 6.02. Found: C, 72.43; H, 4.66; N, 5.91.

Workup

temperatureAfter cooling to room temperature
extractionextracted with AcOEt
washThe extract was washed with water and brine
dry with materialdried over MgSO4
concentrationconcentrated under reduced pressure
customThe residue was recrystallized from hexane/THF

Sources & evidence

ORD record: ord-f656362e5d324acfbc31ed8f63b31f61
Source dataset: uspto-grants-2014_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08778944B2

Reaction notes

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