2-(4-(DifluoroMethyl)phenyl)-4,4,5,5-tetraMethyl-1,3,2-dioxaborolane

2-(4-(DifluoroMethyl)phenyl)-4,4,5,5-tetraMethyl-1,3,2-dioxaborolane Property

Boiling point:

307.6±37.0 °C(Predicted)

Density 

1.09±0.1 g/cm3(Predicted)

storage temp. 

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

Appearance

White to off-white Solid

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P270Do not eat, drink or smoke when using this product.

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

P301+P312IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell.

P302+P352IF ON SKIN: wash with plenty of soap and water.

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

P321Specific treatment (see … on this label).

P330Rinse mouth.

P332+P313IF SKIN irritation occurs: Get medical advice/attention.

P362Take off contaminated clothing and wash before reuse.

P501Dispose of contents/container to..…

2-(4-(DifluoroMethyl)phenyl)-4,4,5,5-tetraMethyl-1,3,2-dioxaborolane Chemical Properties,Usage,Production

Synthesis

General procedure for the synthesis of 4-(difluoromethyl)phenylboronic acid pinacol ester from 1-bromo-4-(difluoromethyl)benzene and pinacol ester of biphenylboronic acid: B. Synthesis of 2-[4-(difluoromethyl)phenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane Under nitrogen protection, [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride (25.25 g, 34.5 mmol) was added in a single step to 1-bromo-4-(difluoromethyl)benzene (160 g, 0.77 mol), 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bis-1,3,2-dioxaborolane (392.5 g, 1.55 mol) and potassium acetate (303 g, 3.09 mol) in a degassed mixture of 1,4-dioxane (2.42 L). The reaction mixture was heated to 100 °C and kept for 18 hours. After completion of the reaction, the mixture was cooled to room temperature and filtered through diatomaceous earth and washed with ethyl acetate (3 L). The filtrate was concentrated in vacuum to give a dark brown oil. This process was repeated three times on batches of 50 g, 160 g and 156 g of 1-bromo-4-(difluoromethyl)benzene (total raw material, 526 g, 2.54 mol) and all the crude products were combined. Two purifications by silica gel chromatography (gradient: 0% to 3% ethyl acetate in heptane solution) gave a yellow-white solid (803 g). The solid was recrystallized from methanol (1.6 L) at -20 °C, the filtrate was concentrated to half its original volume, cooled and the resulting solid was collected by filtration. The combined solids (426 g) were recrystallized from heptane (500 mL) at -20 °C, then melted and poured into methanol (200 mL) cooled in a methanol-ice bath. The mixture was crushed and filtered to give the target product as a solid. Yield: 250.7 g, 0.987 mmol, 39% yield. 1H NMR (400 MHz, CDCl3) δ 1.37 (s, 12H), 6.65 (t, J = 56.4 Hz, 1H), 7.52 (br d, J = 8.1 Hz, 2H), 7.92 (br d, J = 8.0 Hz, 2H).

References

[1] Patent: US2012/214791, 2012, A1. Location in patent: Page/Page column 27
[2] Patent: WO2012/3283, 2012, A1. Location in patent: Page/Page column 165