4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)indolin-2-one

4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)indolin-2-one Property

Boiling point:

427.9±45.0 °C(Predicted)

Density 

1.16±0.1 g/cm3(Predicted)

storage temp. 

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

pka

14.17±0.20(Predicted)

form 

solid

color 

Brown

Safety

HS Code 

2933998090

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H317May cause an allergic skin reaction

H319Causes serious eye irritation

Precautionary statements

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

P280Wear protective gloves/protective clothing/eye protection/face protection.

4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)indolin-2-one Chemical Properties,Usage,Production

Synthesis

The general procedure for the synthesis of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)indol-2-one from 4-bromoindolone and pinacol bis(boronic acid) ester is as follows: 1. in a dry reaction vial, 4-bromodihydroindol-2-one (1.038 g, 4.90 mmol), pinacol ester of bisboronic acid (1.903 g, 7.49 mmol), [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride complexed with dichloromethane (0.601 g, 0.73 mmol) and potassium acetate (1.480 g , 15.08 mmol) in a solution of 1,4-dioxane (30 mL). 2. The reaction mixture was stirred at 110 °C for 2 hours. 3. After completion of the reaction, the mixture was cooled to room temperature and filtered through a cartridge containing 10 g of diatomaceous earth. 4. The filter cake was washed with ethyl acetate (3 x 30 mL), the filtrates were combined and concentrated under vacuum to give a brown liquid. 5. The crude product was dissolved in dichloromethane (about 10 mL) and purified by passing through a 100 g SNAP silica gel column using a Biotage SP4 semi-automated fast column chromatography system eluting with a gradient of 20% to 50% ethyl acetate in cyclohexane solution. 6. Fractions containing the target product were collected, combined and concentrated under vacuum. 7. The concentrate was dissolved in dichloromethane (~10 mL), transferred to a pre-weighed vial and the solvent was evaporated under a stream of nitrogen. 8. The residue was ground with ether (5 x 5 mL) and the supernatant was precipitated by decantation each time and finally dried under vacuum under a stream of nitrogen to afford the milky white solid product 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)dihydroindol-2-one (941.8 mg, 3.63 mmol, 74% yield). Product characterization: LCMS (2 min form): retention time Rt = 0.93 min, [MH]+ = 260.3.

References

[1] Patent: WO2017/174621, 2017, A1. Location in patent: Page/Page column 88
[2] Patent: WO2017/202742, 2017, A1. Location in patent: Page/Page column 42; 43; 97; 98