5-Chloro-1-pentyne

5-Chloro-1-pentyne Property

Melting point:

-61°C (estimate)

Boiling point:

67-69 °C145 mm Hg(lit.)

Density 

0.968 g/mL at 25 °C(lit.)

refractive index 

n20/D 1.444(lit.)

Flash point:

60 °F

storage temp. 

2-8°C

solubility 

Chloroform, Methanol (Slightly)

form 

Liquid

Specific Gravity

0.968

color 

Clear colorless to light brown

Water Solubility 

Not miscible in water.

BRN 

1736710

CAS DataBase Reference

14267-92-6(CAS DataBase Reference)

NIST Chemistry Reference

5-Chloro-1-pentyne(14267-92-6)

EPA Substance Registry System

1-Pentyne, 5-chloro- (14267-92-6)

Safety

Hazard Codes 

F,Xi

Risk Statements 

11-38-36/37/38

Safety Statements 

23-24/25-16

RIDADR 

UN 1993 3/PG 2

WGK Germany 

3

Hazard Note 

Irritant

TSCA 

Yes

HazardClass 

3

PackingGroup 

II

HS Code 

29032900

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H225Highly Flammable liquid and vapour

H315Causes skin irritation

Precautionary statements

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

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

5-Chloro-1-pentyne Chemical Properties,Usage,Production

Chemical Properties

CLEAR COLOURLESS TO LIGHT BROWN LIQUID

Uses

5-Chloro-1-pentyne is used with α-diazoesters in a copper-catalyzed synthesis of pyrazoles. It is also used in the synthesis of 5-chloro-2-trimethylstannyl-1-pentene by reacting with Me3SnCu.Me2S.

Uses

5-Chloro-1-pentyne was used in the synthesis of 5-chloro-2-trimethylstannyl-1-pentene by reacting with Me₃SnCu.Me₂S. It was also used with α-diazoesters in a copper-catalyzed synthesis of pyrazoles.

Synthesis

General procedure for the synthesis of 5-chloro-1-pentyne from 4-pentyn-1-ol: The reaction system was first cooled to 15 °C, followed by the addition of 540 g (6.42 mol) of 4-pentyn-1-ol and 682 g (6.74 mol) of triethylamine to 975 g (7.70 mol) of o-chlorotoluene with stirring and mixing. 772 g (6.74 mol) of methanesulfonyl chloride was slowly added dropwise over a period of 2 h. The internal temperature of the reaction was controlled to be maintained between 15-20 °C. After the dropwise addition was completed, stirring was continued for 30 minutes to ensure that the reaction was complete and the reaction mixture was obtained. Subsequently, the reaction mixture was heated to 90 °C and stirred continuously at this temperature for 2 hours. After completion of the reaction, the mixture was cooled to room temperature. Triethylamine and methanesulfonyl chloride derived by-products were removed from the reaction mixture by washing with water. The organic phase was separated and dried with magnesium sulfate to give 1651 g of organic phase containing 581 g (5.66 mol) of 5-chloro-1-pentynylene in 88.2% reaction yield. The organic phase was mainly composed of o-chlorotoluene (boiling point: 159 °C) and 5-chloro-1-pentyne (boiling point: 113 °C). Finally, the organic phase was purified by decompression distillation to give 584.2 g of 5-chloro-1-pentynyne with 98.2% purity, and the yield of the distillation process was 98.4%.

References

[1] Patent: JP2016/94366, 2016, A. Location in patent: Paragraph 0039; 0040
[2] Organic Letters, 2014, vol. 16, # 6, p. 1720 - 1723
[3] Journal of the Chemical Society, 1950, p. 3650,3655