1: 35.8 percent / pyridine / Ambient temperature 2: 100 percent / NaOCH3 / methanol; tetrahydrofuran / 1 h / Ambient temperature 3: 95 percent / pyridine / Ambient temperature 4: 94 percent / N-bromosuccinimide (NBS), α,α'-azobis(isobutyronitrile) (AIBN) / CCl4 / 0.5 h / 65 °C 5: 40 mg / 1,5-diazabicyclo<5.4.0>undec-5-ene (DBU) / tetrahydrofuran / 2.5 h / Ambient temperature View Scheme