4-(4,4,5,5-TETRAMETHYL-[1,3,2]DIOXABOROLAN-2-YL)-1H-INDAZOLE Chemical Properties

Melting point:

139-142℃

storage temp. 

Inert atmosphere,2-8°C

form 

solid

color 

White to off-white

InChI

InChI=1S/C13H17BN2O2/c1-12(2)13(3,4)18-14(17-12)10-6-5-7-11-9(10)8-15-16-11/h5-8H,1-4H3,(H,15,16)

InChIKey

YRPXZCWDXBNPBD-UHFFFAOYSA-N

SMILES

N1C2=C(C(B3OC(C)(C)C(C)(C)O3)=CC=C2)C=N1

Safety Information

HS Code 

2933998090

4-(4,4,5,5-TETRAMETHYL-[1,3,2]DIOXABOROLAN-2-YL)-1H-INDAZOLE Usage And Synthesis

Synthesis

To a solution of 4-bromo-1H-indazole (500 mg, 2.54 mmol) and bis(pinacolato)diboron (1.5 eq, 3.81 mmol) in dimethyl sulfoxide (DMSO, 20 mL) was added dry potassium acetate (3.0 eq, 7.61 mmol, 747 mg) and PdCl2(dppf)2 (3 mol%, 0.076 mmol, 62 mg). The reaction mixture was degassed with argon and the reaction was heated at 80 °C for 40 hours. After completion of the reaction, it was cooled to room temperature and the reaction mixture was partitioned between water (50 mL) and ether (3 x 50 mL). The organic layers were combined, washed with brine (50 mL), separated and dried over anhydrous magnesium sulfate (MgSO4). The crude product was purified by column chromatography using 30%-40% ethyl acetate/petroleum ether as eluent to give a non-separable 3:1 mixture of 1H-indazole-4-boronic acid pinacol ester (369 mg, 60%) and unreacted 4-bromo-1H-indazole (60 mg, 20%). The mixture was a yellow gel that solidified to an off-white solid upon standing.1H NMR (400 MHz, DMSO-d6) data were as follows:1H-indazole-4-boronic acid pinacol ester (70): δ 1.41 (12H, s), 7.40 (1H, dd, J = 8.4 Hz, 6.9 Hz), 7.59 (1H, d, J = 8.4 Hz), 7.67 (1H, d, J = 6.9 Hz), 10.00 (1H, br s), 8.45 (1H, s); 4-bromo-1H-indazole: δ 7.40 (1H, m), 7.18 (1H, t, J = 7.9 Hz), 7.50 (1H, d, J = 9.1 Hz), 7.77 (1H, d, J = 7.9 Hz), 8.09 (1H, s). The impurity peak appeared at δ 1.25.

References

[1] Patent: WO2007/42806, 2007, A1. Location in patent: Page/Page column 34-35
[2] Patent: WO2011/130628, 2011, A1. Location in patent: Page/Page column 128
[3] Patent: US2013/102595, 2013, A1. Location in patent: Paragraph 0173
[4] Patent: JP2015/187145, 2015, A. Location in patent: Paragraph 0171
[5] Bioorganic and Medicinal Chemistry, 2014, vol. 22, # 3, p. 1156 - 1162

4-(4,4,5,5-TETRAMETHYL-[1,3,2]DIOXABOROLAN-2-YL)-1H-INDAZOLE(885618-33-7)Related Product Information

• 1-Methyl-1H-indazole-4-boronic acid pinacol ester
• Indazole-4-boronic acid, hydrochloride
• 6-FLUORO-4-(4,4,5,5-TETRAMETHYL-[1,3,2]DIOXABOROLAN-2-YL)-1H-INDAZOLE
• 4-(4,4,5,5-TETRAMETHYL-[1,3,2]DIOXABOROLAN-2-YL)-1H-INDAZOLE