1-Butyl-4-eth-1-ynylbenzene

1-Butyl-4-eth-1-ynylbenzene Property

Boiling point:

70-71°C 3mm

Density 

0.906 g/mL at 25 °C(lit.)

refractive index 

n20/D 1.527(lit.)

Flash point:

215 °F

storage temp. 

Inert atmosphere,2-8°C

form 

clear liquid

color 

Colorless to Light orange to Yellow

Specific Gravity

0.93

CAS DataBase Reference

79887-09-5(CAS DataBase Reference)

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-36-37/39-36/37/39

WGK Germany 

3

Hazard Note 

Irritant

HS Code 

29029090

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.

P271Use only outdoors or in a well-ventilated area.

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.

1-Butyl-4-eth-1-ynylbenzene Chemical Properties,Usage,Production

Chemical Properties

Light yellow liquid

Uses

4-Butylphenylacetylene is a useful research chemical, an intermediates of Liquid Crystals.

Synthesis

General steps: 1. Under argon protection, Pd(OAc)? (13.5 mg, 0.06 mmol), PPh? (31.5 mg, 0.12 mmol), CuI (5.7 mg, 0.03 mmol) and 1-bromo-4-butylbenzene (639 mg, 3.00 mmol) were dissolved in triethylamine (1 mL). A solution of trimethylmethylsilylacetylene (324 mg, 3.30 mmol) was subsequently added. 2. The reaction mixture was stirred at 80 °C for 4 h. Upon completion of the reaction, it was acidified with 1N HCl aqueous solution. 3. Deionized water and EtOAc were added, partitioned and the organic layer was collected. The aqueous layer was extracted with EtOAc and the organic layers were combined. 4. The organic layer was washed with saturated brine, dried over anhydrous MgSO?, filtered and concentrated under reduced pressure. 5. The crude product was purified by silica gel column chromatography with the eluent of petroleum ether/EtOAc (100:1, v/v, Rf = 0.43) to afford 1-(4-butylphenyl)-2-trimethylsilylacetylene (S8) as a light yellow oil (550 mg, 2.40 mmol, 80% yield). 6. S8 (550 mg, 2.40 mmol) and K?CO? (495 mg, 3.58 mmol) were suspended in MeOH (12 mL) and stirred at room temperature for 4 hours. 7. The reaction mixture was filtered through diatomaceous earth and the filtrate was concentrated under reduced pressure. 8. Deionized water and EtOAc were added, partitioned and the organic layer was collected. The aqueous layer was extracted with EtOAc and the organic layers were combined. 9. The organic layer was washed with saturated brine, dried over anhydrous MgSO?, filtered and concentrated under reduced pressure. 10. The crude product was purified by silica gel column chromatography with the eluent petroleum ether/EtOAc (50:1, v/v, Rf = 0.50) to afford 1-butyl-4-ethynylbenzene (S9) as a light yellow oil (340 mg, 2.15 mmol, 90% yield). 11. Under argon protection, Pd(OAc)? (8.8 mg, 0.039 mmol), PPh? (20.5 mg, 0.078 mmol), CuI (3.7 mg, 0.020 mmol) and S9 (340 mg, 2.15 mmol) were dissolved in triethylamine (1 mL). 12. The reaction mixture was stirred at 80 °C for 4 h. Upon completion of the reaction, it was acidified with 1N HCl aqueous solution. 13. The reaction mixture was treated according to the post-synthesis treatment of S8, and the crude product was purified by silica gel column chromatography with the eluent of petroleum ether/EtOAc (50:1, v/v, Rf = 0.30) to afford 1-butyl-4-phenylethynyl (4c) as a yellow solid (340 mg, 1.17 mmol, 60% yield).

References

[1] Bulletin of the Chemical Society of Japan, 2018, vol. 91, # 7, p. 1069 - 1074
[2] Journal of Medicinal Chemistry, 1991, vol. 34, # 4, p. 1440 - 1446