2,4-Dimethoxybenzeneboronic acid

2,4-Dimethoxybenzeneboronic acid Property

Melting point:

125-127 °C (lit.)

Boiling point:

361.1±52.0 °C(Predicted)

Density 

1.19±0.1 g/cm3(Predicted)

storage temp. 

Keep in dark place,Sealed in dry,Room Temperature

solubility 

soluble in Methanol

form 

powder to crystal

pka

8.98±0.58(Predicted)

color 

White to Dark green

BRN 

4744213

InChI

InChI=1S/C8H11BO4/c1-12-6-3-4-7(9(10)11)8(5-6)13-2/h3-5,10-11H,1-2H3

InChIKey

SQTUYFKNCCBFRR-UHFFFAOYSA-N

SMILES

B(C1=CC=C(OC)C=C1OC)(O)O

CAS DataBase Reference

133730-34-4(CAS DataBase Reference)

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

37/39-26-36/37-24/25

WGK Germany 

3

Hazard Note 

Irritant/Keep Cold

HazardClass 

IRRITANT

HS Code 

29420000

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.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

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

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

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

P405Store locked up.

2,4-Dimethoxybenzeneboronic acid Chemical Properties,Usage,Production

Uses

2,4-Dimethoxyphenylboronic acid can be used:

•  As a reactant in meatal-catalyzed Suzuki−Miyaura cross-coupling reaction.

•  To prepare hydroxy(trimethoxy)phenanthrene by cross-coupling with bromo(benzyloxy)methoxybenzaldehyde followed by condensation and debenzylation reaction.

• To synthesize 2,4-dimethoxy-1-(trifluoromethyl)benzene via Cu-catalyzed trifluoromethylation reaction.

Uses

Reactant for:

• Suzuki-Miyaura and Negishi couplings.

Chemical Properties

white to beige or pink moist powder

Uses

suzuki reaction

Uses

2,4-Dimethoxyphenylboronic acid can be used:

• As a reactant in meatal-catalyzed Suzuki?Miyaura cross-coupling reaction.
• To prepare hydroxy(trimethoxy)phenanthrene by cross-coupling with bromo(benzyloxy)methoxybenzaldehyde followed by condensation and debenzylation reaction.
• To synthesize 2,4-dimethoxy-1-(trifluoromethyl)benzene via Cu-catalyzed trifluoromethylation reaction.

Synthesis

The general procedure for the synthesis of 2,4-dimethoxyphenylboronic acid from 2,4-dimethoxybromobenzene was as follows: first, 576 μL of 1-bromo-2,4-dimethoxybenzene was dissolved in 5.8 mL of tetrahydrofuran, which was cooled to -78 °C under argon protection. Subsequently, 3 mL of 1.6 mol/L n-butyllithium hexane solution was slowly added dropwise. After the dropwise addition, 1.1 mL of triisopropyl borate was added and the reaction continued to be stirred at -78 °C for 40 minutes, after which it was brought to room temperature and stirred for 2 hours. Upon completion of the reaction, the reaction mixture was quenched by adding 40 mL of water and 1 mL of 5N hydrochloric acid to the reaction mixture and then extracted with 50 mL of ethyl acetate. The organic layer was dried with anhydrous magnesium sulfate and the solvent was removed by distillation under reduced pressure. Finally, 610.2 mg of 2,4-dimethoxyphenylboronic acid was purified by silica gel column chromatography (eluent ratio hexane:ethyl acetate=2:1). The product was characterized by 1H-NMR (CDCl3): δ (ppm) 3.85 (3H, s), 3.89 (3H, s), 5.81 (2H, s), 6.46 (1H, s), 6.56 (1H, dd, J = 2.0,8.4 Hz), 7.77 (1H, d, J = 8.4 Hz).

References

[1] Organic Letters, 2000, vol. 2, # 5, p. 629 - 631
[2] Journal of the American Chemical Society, 2006, vol. 128, # 22, p. 7176 - 7178
[3] Journal of the American Chemical Society,
[4] Journal of the American Chemical Society, 2009, vol. 131, p. 4710 - 4719
[5] Patent: US2014/30209, 2014, A1. Location in patent: Paragraph 0295; 0296