With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.20532-33-6,5-Chlorobenzothiophene,as a common compound, the synthetic route is as follows.
i) 5-Chloro-benzo[b]thiophene-3-sulfonyl chloride To a solution of 5-chloro-benzo[b]thiophene (Synchem, 1.0 g, 6 mmol) in 1,2-dichloroethane (10 mL) was added sulfur trioxide dimethylformamide complex (1.1 g, 7.2 mmol). The reaction mixture was stirred at 85 C. for 3 h, cooled down to about 50 C., and thionyl chloride (0.92 g, 7.8 mmol) was added. The mixture was further stirred at 80 C. for 1 h, cooled down and chromatographed on silica gel using heptane/ethyl acetate as eluent to obtain 5-chloro-benzo[b]thiophene-3-sulfonyl chloride (1.25 g) as colorless crystals. MS (EI) m/e 265.8 (M), 20532-33-6
As the paragraph descriping shows that 20532-33-6 is playing an increasingly important role.
Reference：
Patent; Hebeisen, Paul; Kitas, Eric A.; Minder, Rudolf E.; Mohr, Peter; Wessel, Hans Peter; US2009/143448; (2009); A1;,
Benzothiophene – Wikipedia
Benzothiophene | C8H6S – PubChem