1: 5-formyl-2,2'-dipyrrylmethane With 1,8-diazabicyclo[5.4.0]undec-7-ene in toluene T=20 - 98°C; 0.0833333 - 0.25 h; 2: magnesium bromide in toluene T=20 - 135°C; 14 - 20.3333 h; Heating / reflux; Product distribution / selectivity;

1,8-diazabicyclo[5.4.0]undec-7-ene in toluene T=115°C; 36 h; Product distribution / selectivity;

trifluoroacetic acid in dichloromethane T=20°C; 1 h;