General description
2-Bromothiophene undergoes metallation-alkylation reaction with various electrophiles to generate various 5-alkylated 2-bromo products. It is coupled with 4-bromoallyl phenyl ether to produce allyl thiophene ether, which is a new type of organic thin film transistor dielectric material.
Application
In dimethylformamide containing tetramethylammonium perchlorate, 2-bromothiophene is electrochemically reduced many mono- and dihalothiophenes on a carbon cathode by cyclic voltammetry and controlled potential electrolysis.
Product Introduction
The 2-Bromothiophene(casno:1003-09-4) is an organic compound with the formula C4H3BrS. The IUPAC name of this chemical is 2-bromothiophene. With the CAS registry number 1003-09-4, it is also named as Bromothiophene. The product's categories are Thiophenes; Halides; Thiophenes & Benzothiophenes; Thiophene & Benzothiophene; Thiophenes & Benzothiophenes. Besides, 2-Bromothiophene(casno:1003-09-4) is a colorless to light yellow transparent liquid, which should be stored in a closed dark and cool place. 2-Bromothiophene(casno:1003-09-4) can be used for organic synthesis and pharmaceutical intermediates.
Chemical Properties
colorless to light yellow liquid. Soluble in ether and acetone, insoluble in water.
Uses
2-Bromothiophene has been used in electrochemical reduction of a number of mono- and dihalothiophenes at carbon cathodes in dimethylformamide containing tetramethylammonium per chlorate by cyclic voltammetry and controlled-potential electrolysis.
Preparation
2-Bromothiophene is synthesized by bromination of thiophene, which is achieved through the following steps: dissolve thiophene in acetic acid, and add bromine in glacial acetic acid solution below 10°C. Water was added to the reaction mixture to precipitate an oily liquid. Extract with ether. Add potassium carbonate to the extract to remove acetic acid, dry it, distill off the ether, and then conduct vacuum distillation to collect fractions at 42-46°C (1.73kPa) to obtain 2-bromothiophene with a yield of 55%.
General Description
2-Bromothiophene undergoes metalation-alkylation reaction with various electrophiles to form various 5-alkylated 2-bromo products. It undergoes coupling with 4-bromo allyl phenyl ether to form allyl phenyl thiophene ether, which is a novel potential dielectric material for organic thin film transistors.
Synthesis
Configure a 500-mL three-neck flask with a condenser tube, stirring bar, and thermometer and place the unit in an ice bath. The condenser tube was connected to a hydrogen bromide gas absorption unit. Thiophene acetaldehyde (79 mL, 84 g, 1.0 mol) and carbon tetrachloride (160 mL, 250 g) were added to the reaction flask, and the temperature of the reaction was controlled to be in the range of 0-5°C with continuous stirring. Bromine (48 mL, 150 g, 1.15 mol) and 40% hydrobromic acid (190 mL) were added slowly dropwise for a controlled time of 80 minutes. After the dropwise addition, the reaction was continued with stirring for 60 min to ensure complete escape of hydrogen bromide gas. The reaction mixture was washed with water, dried and then distilled at atmospheric pressure to recover the solvent. The crude product was transferred to a 250 mL distillation flask for reduced pressure distillation and the fraction was collected at 58-62°C/7 kPa to give the colorless liquid 2-bromothiophene (85 mL, 143 g) in 88.1% yield and 98.4% purity.
References
[1] Synthesis, 1988, # 11, p. 890 - 891
[2] Synthetic Communications, 2008, vol. 38, # 16, p. 2814 - 2819
[3] Journal of Organic Chemistry, 1993, vol. 58, # 11, p. 3072 - 3075
[4] Journal of the Chemical Society, Chemical Communications, 1982, # 14, p. 778 - 779
[5] Patent: CN104447679, 2016, B. Location in patent: Paragraph 0028-0029
