23784-96-5

74168-69-7

23784-96-5

Under nitrogen protection, 5-chloro-2-thiophene methanol (500 mg, 3.37 mmol) was dissolved in tetrahydrofuran (10 mL) and cooled to 0 °C. Subsequently, CN (482 mg, 4.05 mmol) was added dropwise. After the dropwise addition, the reaction mixture was warmed up to 50 °C for 3 h, during which the reaction progress was monitored by TLC. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure to afford 480 mg of 2-chloro-5-chloromethylthiophene in yellow liquid form (yield: 85.5%), which could be used directly in the subsequent reaction without further purification.