Chemical Properties
Off-White Solid
Uses
Intermediate in the preparation of Rotigotine
Uses
2-(2-thienyl)ethyl toluene-p-sulphonate is an important intermediate of the synthetic drug clopidogrel. Clopidogrel is a new and effective medicament for resisting platelet aggregation. Clinically, it is widely used in the treatment and prevention of myocardial infarction, cardiovascular and cerebrovascular diseases, etc.
Synthesis
GENERAL STEPS: 2-Thiophene ethanol (0.87 mol) and p-toluenesulfonyl chloride (184 g, 0.97 mol) were added sequentially to a 1 L three-necked flask. Under the condition of ice-water bath, triethylamine (98 g, 0.97 mol) was slowly added dropwise and the temperature of the reaction solution was controlled not to exceed 20 °C. The reaction system was then purified by the reaction of the reaction solution. After the dropwise addition, the reaction system was heated to 35 °C with continuous stirring. Samples were taken after 24 h and 27 h, respectively, and the progress of the reaction was monitored by thin layer chromatography (TLC) until the reaction was complete. After completion of the reaction, heating was stopped and filtration was carried out. The filter cake was washed with appropriate amount of dichloromethane, the organic layers were combined and dried with anhydrous sodium sulfate for 2 hours. The desiccant was removed by filtration and the desiccant was washed with a small amount of dichloromethane. The combined filtrates were concentrated under reduced pressure until constant weight to give the brown oily product 2-thiophene ethanol p-toluenesulfonate (203 g, 98% yield).
References
[1] Patent: CN103467486, 2016, B. Location in patent: Paragraph 0094-0096
[2] Patent: US2007/225320, 2007, A1. Location in patent: Page/Page column 5
[3] Patent: CN107056801, 2017, A. Location in patent: Paragraph 0016
[4] Patent: US2007/225320, 2007, A1. Location in patent: Page/Page column 7
[5] Patent: WO2011/161255, 2011, A2. Location in patent: Page/Page column 36
