(3-Bromophenyl)boronic acid → 4-(3-bromophenyl)-1-methyl-1H-pyrazole

HRID 653625Notes

Reaction equation

HRID 653625 reaction equation
[CH3:1][N:2]1[CH:6]=[C:5](I)[CH:4]=[N:3]1.[Br:8][C:9]1[CH:10]=[C:11](B(O)O)[CH:12]=[CH:13][CH:14]=1.BrC1C=C(C2C=NC=CC=2)C=CC=1>>[Br:8][C:9]1[CH:14]=[C:13]([C:5]2[CH:4]=[N:3][N:2]([CH3:1])[CH:6]=2)[CH:12]=[CH:11][CH:10]=1

Participants

4

Reactant 3

HCID 2734318(3-Bromophenyl)boronic acidHCID 27347731-Methyl-4-iodo-1H-pyrazoleHCID 131504013-(3-Bromophenyl)pyridine

Product 1

HCID 198894254-(3-bromophenyl)-1-methyl-1H-pyrazole

Procedure

The reaction of 1-methyl-4-iodopyrazole (Liljefors, S., and Gronowitz S. Chemica Scripta, 15, 102-9 (1980)) (1.3 g, 6.2 mmol) with 3-bromophenyl boronic acid (1.24 g, 6.2 mmol) using the procedure for the preparation of 3-(3'-bromophenyl)pyridine gave crude 4-(m-bromophenyl)-1-methylpyrazole which was chromatographed on a column of Bakers Silica Gel (60-200 mesh) packed and eluted with CH2Cl2. The less polar fractions contained undesired, incorrectly coupled products while the later more polar fractions contained the desired product (0.82 g, 56% yield).

Sources & evidence

ORD record
ord-fcfb4211042d4f978665a46a752f8b25
Source dataset
uspto-grants-1992_07
Patent number
US05128335

Reaction notes

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