potassium hydroxide in water; N,N-dimethyl-formamide 1.) 90 deg C - 100 deg C, 2 d; 2.) 25 deg C - 30 deg C, 1 d.;

toluene-4-sulfonic acid in toluene 1.) reflux, 6 h; 2.) 25 deg C - 30 deg C, 18 h.;

1: 98 percent / 85percent KOH / H2O / 1.) 90 deg C - 100 deg C, 24 h; 2.) 25 deg C - 30 deg C, 18 h. 2: 84 percent / p-toluenesulfonic acid / toluene / 1.) reflux, 6 h; 2.) 25 deg C - 30 deg C, 18 h. View Scheme

pyridine