Tetrahydrofuran → 4-chloro-1-methyl-5-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Reaction equation

[CH3:1][N:2]1[C:6]([B:7]2[O:11][C:10]([CH3:13])([CH3:12])[C:9]([CH3:15])([CH3:14])[O:8]2)=[CH:5][CH:4]=[N:3]1.[Cl:16]N1C(=O)CCC1=O.O1CCCC1>>[Cl:16][C:5]1[CH:4]=[N:3][N:2]([CH3:1])[C:6]=1[B:7]1[O:11][C:10]([CH3:13])([CH3:12])[C:9]([CH3:15])([CH3:14])[O:8]1

Participants

Reactant 3

HCID 8028Tetrahydrofuran

HCID 31398Chlorosuccinimide

HCID 49129081-methyl-5-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Product 1

HCID 755256674-chloro-1-methyl-5-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazoleYield 92.6%

Procedure

A solution of 1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (1.00 g, 4.81 mmol) and N-chlorosuccinimide (0.671 g, 5.05 mmol) in tetrahydrofuran (10 mL, 100 mmol) was stirred at 70° C. for 2 hrs. The reaction mixture was concentrated under reduced pressure and the residue was purified by combi-flash chromatography and eluted with EtOAc/hexane (10-80%). The purification afforded 1.08 g (78% yield) of the desired product as white solid.