Scheme 1

Synthesis of intermediate compound 2-bromo-5-(bromomethyl)thiophene (2) and 2-(bromomethyl)-5-aryl-thiophenes 3a–i. Conditions: i, 1, (1 eq, 20.4 mmol), NBS (2.1 eq, 42.84 mmol), CCl₄ (9–10 mL). Procedure: reflux 1 and NBS in CCl₄ for 4–5 hours; Condition ii, 2 (1 eq, 0.976 mmol), Pd(PPh₃)₄ (2.5 mol%) aryl boronic acid (1.1 eq, 1.073 mmol), K₃PO₄ (2 eq, 1x.952 mmol), 1,4-dioxane/H₂O (4:1) (Table 1), 12 h, 90°C.