1-Methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole

1-Methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole Property

Melting point:

110-114 °C (lit.)

Boiling point:

391.3±15.0 °C(Predicted)

Density 

1.05±0.1 g/cm3(Predicted)

storage temp. 

under inert gas (nitrogen or Argon) at 2-8°C

form 

solid

Appearance

Off-white to light yellow Solid

InChI

InChI=1S/C15H20BNO2/c1-14(2)15(3,4)19-16(18-14)12-6-7-13-11(10-12)8-9-17(13)5/h6-10H,1-5H3

InChIKey

JQLYKUPEQYNDFF-UHFFFAOYSA-N

SMILES

N1(C)C2=C(C=C(B3OC(C)(C)C(C)(C)O3)C=C2)C=C1

Safety

Hazard Codes 

Xi

Safety Statements 

22-24/25

WGK Germany 

3

Hazard Note 

Irritant

HS Code 

2933299090

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

1-Methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole Chemical Properties,Usage,Production

Chemical Properties

off-white powder

Synthesis

The general procedure for the synthesis of 1-methylindole-5-boronic acid pinacol ester from 5-bromo-1-methyl-1H-indole and biboronic acid pinacol ester is as follows: the synthesis was carried out according to the literature method with appropriate adjustments. To an 8-dram vial equipped with a magnetic stirrer were sequentially added pinacol bis(boronic acid) ester (2 mmol, 508 mg), 5-bromo-1-methyl-1H-indole (2.1 mmol, 441 mg), [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride (0.06 mmol, 44 mg), potassium acetate (6 mmol, 589 mg), and degassed 1,1'-bis(diphenylphosphino)ferrocene(III). ), and degassed 1,4-dioxane (10 mL). The reaction mixture was purged under a strong stream of nitrogen for 5 min to deoxygenate, followed by transferring the reaction system to an oil bath preheated to 80 °C with continuous stirring for 48 h. The reaction was carried out in a cooled room with a temperature range of 0.5 °F to 0.5 °F. Upon completion of the reaction, it was cooled to room temperature and the reaction mixture was filtered through a diatomaceous earth pad and washed with ethyl acetate (50 mL). The filtrates were combined and concentrated under reduced pressure to remove the solvent. The crude product was purified by fast column chromatography with petroleum ether as eluent, followed by a 5% to 12% gradient elution of ether/petroleum ether to afford 342 mg (67% yield) of the target product, 1-methylindole-5-boronic acid pinacol ester, as a white solid.

References

[1] Synlett, 2018, vol. 29, # 15, p. 2031 - 2034
[2] ACS Catalysis, 2018, vol. 8, # 5, p. 4049 - 4054
[3] Angewandte Chemie - International Edition, 2018, vol. 57, # 34, p. 10999 - 11003
[4] Angew. Chem., 2018, # 130, p. 11165 - 11169,5
[5] Patent: WO2016/180537, 2016, A1. Location in patent: Page/Page column 133