Synthesis
In a 250 ml three-necked flask fitted with a thermometer, stirrer, iodine (0.15 mol) was added to a mixture of thiophenecarboxaldehyde (R = H, 0.1 mol), acetonitrile (100 ml), and ammonia (2.0 mol). stirring was carried out at 10 C, and the reaction time was controlled by HPLC tracking. Then Na2S2O3 was added to remove unreacted iodine, cooled to 0 C and stirred for 1 h. A large number of crystals were produced. Filtration and drying gave the product as a pale yellow solid in 90% yield.
A 250-mL three-necked flask was fitted with a thermometer, stirrer. Tetrahydrofuran (100 ml) was added and cooled to 0C, then sodium tert-butanol (0.5 mol) was added. Acetonitrile (0.3 mol) was added dropwise, keeping the internal temperature at 0C and stirring for 10 minutes. Thiophenecarbonitrile (0.1 mol, R = H) was added dropwise at 0 C and then stirred for 30 min (HPLC trace). The reaction was aborted by the addition of hydrochloric acid and crushed ice, slowly warmed to room temperature and stirring was continued for 3 hours. The reaction was extracted using eth
Ethyl acetate was extracted, dried and concentrated to give 2-thienyl acetonitrile as a pale yellow solid in 70% yield and 99.2% purity (HPLC).
