5-AMINO-2-METHYLPHENYLBORONIC ACID, PINACOL ESTER

5-AMINO-2-METHYLPHENYLBORONIC ACID, PINACOL ESTER Property

Melting point:

82-86°C

Boiling point:

366.2±35.0 °C(Predicted)

Density 

1.03

storage temp. 

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

form 

solid

pka

5.01±0.10(Predicted)

Appearance

White to off-white Solid

InChI

InChI=1S/C13H20BNO2/c1-9-6-7-10(15)8-11(9)14-16-12(2,3)13(4,5)17-14/h6-8H,15H2,1-5H3

InChIKey

HPNBWHDRLCVZFV-UHFFFAOYSA-N

SMILES

C1(N)=CC=C(C)C(B2OC(C)(C)C(C)(C)O2)=C1

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38-38-36

Safety Statements 

26-36/37/39

WGK Germany 

2

HS Code 

2931900090

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

Precautionary statements

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

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

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.

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

P337+P313IF eye irritation persists: Get medical advice/attention.

5-AMINO-2-METHYLPHENYLBORONIC ACID, PINACOL ESTER Chemical Properties,Usage,Production

Synthesis

Using 3-iodo-4-methylaniline (1.97 g, 8.45 mmol) and pinacol ester of bis(diphenylphosphino)borate (2.32 g, 9.13 mmol) as raw materials, pinacol ester of bis(boronic acid) was dissolved in DMSO (23 mL) under the protection of argon gas, and potassium acetate (2.87 g, 29.2 mmol) and [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride were added sequentially ( 345 mg, 0.423 mmol). The reaction mixture was stirred at 80 °C for 4 hours. After completion of the reaction, ethyl acetate and water were added to the mixture, the insoluble material was removed by filtration through diatomaceous earth and the organic phase was extracted with ethyl acetate. The organic layer was washed sequentially with water and brine and dried over anhydrous magnesium sulfate. The solvent was removed by concentration under reduced pressure and the residue was purified by silica gel column chromatography (eluent: ethyl acetate/hexane=6/1) to afford the target product 4-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (Compound A4, 1.36 g, 69% yield). The product was characterized by 1H NMR (300 MHz, CDCl3): δ 1.33 (s, 12H), 2.42 (s, 3H), 3.51 (br s, 2H), 6.68 (dd, J = 8.1,2.7Hz, 1H), 6.97 (d, J = 8.1Hz, 1H), 7.11 (d, J = 2.7Hz, 1H).

References

[1] Patent: EP2269993, 2011, A1. Location in patent: Page/Page column 52
[2] Journal of Medicinal Chemistry, 2006, vol. 49, # 19, p. 5671 - 5686
[3] Patent: US2010/197688, 2010, A1. Location in patent: Page/Page column 16
[4] Patent: WO2015/24905, 2015, A1. Location in patent: Paragraph 00216-00217; 00344-00346
[5] Patent: US2015/80391, 2015, A1. Location in patent: Paragraph 0439; 0440; 0441; 0655; 0656; 0657