Triethylamine → 4-bromo-1-(tris(4-methoxyphenyl)methyl)-1H-pyrazole

HRID 512609Notes

Reaction equation

HRID 512609 reaction equation
[Br:1][C:2]1[CH:3]=[N:4][NH:5][CH:6]=1.[CH3:7][O:8][C:9]1[CH:32]=[CH:31][C:12]([C:13](Cl)([C:22]2[CH:27]=[CH:26][C:25]([O:28][CH3:29])=[CH:24][CH:23]=2)[C:14]2[CH:19]=[CH:18][C:17]([O:20][CH3:21])=[CH:16][CH:15]=2)=[CH:11][CH:10]=1.C(N(CC)CC)C>CN(C=O)C>[Br:1][C:2]1[CH:3]=[N:4][N:5]([C:13]([C:12]2[CH:11]=[CH:10][C:9]([O:8][CH3:7])=[CH:32][CH:31]=2)([C:22]2[CH:27]=[CH:26][C:25]([O:28][CH3:29])=[CH:24][CH:23]=2)[C:14]2[CH:19]=[CH:18][C:17]([O:20][CH3:21])=[CH:16][CH:15]=2)[CH:6]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 163754-BromopyrazoleHCID 6305054,4',4''-Trimethoxytrityl chloride

Product 1

HCID 584320664-bromo-1-(tris(4-methoxyphenyl)methyl)-1H-pyrazoleYield 52%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a suspension of 4-bromopyrazole (1.5 g, 10.2 mmol) and 4,4′,4″-trimethoxytrityl chloride (4.5 g, 12.2 mmol) in anhydrous DMF (20 mL) under argon was added triethylamine (3 mL, 21.5 mmol) and the mixture was cooled over an ice bath. After stirring for 10 min, the ice bath was removed and the reaction stirred for 2.5 hrs. The mixture was diluted with H2O and extracted with EtOAc. The combined organics were washed with H2O three times then saturated aqueous NaHCO3 and brine. The solution was dried over Na2SO4 and concentrated in vacuo. The crude oil was recrystallized from isopropanol to give 4-bromo-1-(tris(4-methoxyphenyl)methyl)-1H-pyrazole as off-white crystals (two batches; 2.55 g, 52% yield).

Workup

  1. temperaturethe mixture was cooled over an ice bath
  2. customthe ice bath was removed
  3. stirringthe reaction stirred for 2.5 hrs
  4. additionThe mixture was diluted with H2O
  5. extractionextracted with EtOAc
  6. washThe combined organics were washed with H2O three times
  7. dry with materialThe solution was dried over Na2SO4
  8. concentrationconcentrated in vacuo
  9. customThe crude oil was recrystallized from isopropanol

Sources & evidence

ORD record
ord-a237615cd613475d9ac4b165943460d6
Source dataset
uspto-grants-2015_08
Patent number
US09102643B2

Reaction notes

Loading…