toluene-4-sulfonic acid in acetone 2 h;

copper(II) sulfate 5 h; Heating;

1: 90 percent / pyridine / Ambient temperature 2: 70 percent / NaH / dimethylformamide / Ambient temperature 3: 92 percent / H2 / 10 percent Pd/C / ethyl acetate / Ambient temperature 4: 75 percent / DBU / 1,2-dichloro-ethane / Ambient temperature 5: trimethylsilyl trifluoromethanesulfonate / 1,2-dichloro-ethane / 0.08 h / Ambient temperature 6: 95 percent / Bu4NF / tetrahydrofuran / Ambient temperature View Scheme

1: 90 percent / pyridine / Ambient temperature 2: 70 percent / NaH / dimethylformamide / Ambient temperature 3: 92 percent / H2 / 10 percent Pd/C / ethyl acetate / Ambient temperature 4: 75 percent / DBU / 1,2-dichloro-ethane / Ambient temperature 5: trimethylsilyl trifluoromethanesulfonate / 1,2-dichloro-ethane / 0.08 h / Ambient temperature 6: 95 percent / Bu4NF / tetrahydrofuran / Ambient temperature 7: 88 percent / pyridine / Ambient temperature View Scheme

pyridine