3-Octylthiophene

Chemical Properties

clear colorless to light yellow liquid

Uses

3-Octylthiophene is used as a starting material in the synthesis of the following 2,5-dibromo-3-octylthiophene, poly(3-butylthiophene)-b-poly(3-octylthiophene), a diblock copoly(3-alkylthiophene), regioregular poly(3-octylthiophene).

General Description

3-Octylthiophene is an alkyl thiophene derivative. It has been synthesized by the reaction of 3-bromothiophene with octylmagnesium bromide.

Synthesis

The general procedure for the synthesis of 3-octylthiophene from 3-bromothiophene and 1-bromooctane is as follows: following the methodology reported in the literature (Chochos CL, Economopoulos SP, Deimede V, Gregoriou VG, Lloyd MT, Malliaras GG, Kallitsis JK, et al. Synthesis of Soluble n-Type Cyano-Substituted Polythiophene Derivatives: Solar Cells. Chem Mater. 2007;111:10732-40), under nitrogen protection, 1-bromooctane (28.7 mL) was slowly added dropwise to a solution of magnesium (4.63 g, 193 mmol) in anhydrous ether (130 mL). The mixture was stirred under nitrogen atmosphere for 2 hours to produce Grignard reagent. Subsequently, the resulting Grignard reagent was slowly added dropwise to a reaction flask containing 3-bromothiophene (19 g, 116.6 mmol) and Ni(dppp)Cl2 (0.31 g, 0.571 mmol). The reaction mixture was heated with stirring for 24 hours. Upon completion of the reaction, the mixture was placed in an ice bath and the reaction was quenched by the addition of 2N HCl and subsequently extracted with ether. The organic layers were combined, dried over anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent. The crude product was purified by hexane column chromatography to afford the colorless oily product 3-octylthiophene (15.54 g, 68% yield).

References

[1] Journal of Organic Chemistry, 2000, vol. 65, # 13, p. 3894 - 3901
[2] Structural Chemistry, 2012, vol. 23, # 6, p. 1751 - 1760
[3] Patent: KR2018/17709, 2018, A. Location in patent: Paragraph 0196; 0199; 0200-0202
[4] Macromolecules, 2011, vol. 44, # 16, p. 6370 - 6381
[5] RSC Advances, 2016, vol. 6, # 82, p. 78984 - 78993