Christian Bruckner, Ross W Boyle, David Dolphin
Synthesis of Polypyrrolic Macrocycles from Meso-Substituted Tripyrrane Compounds
A compound of Formula I:
wherein: Q represents identical alkyl groups, cycloalkyl groups having from 5 to 7 ring atoms, or aryl or heteroaryl groups having from 5 to 12 ring atoms and R represents identical hydrogen, alkyl, alcohol or carbonyl-conlaining groups; or a composition containing from 5 to 100 mole % by weight of the compound of Formula I. A novel method for synthesizing the compound of Formula I comprises the steps of: (a) reacting a compound of the formula: Q-CHO or Q-CH(OS)(OS') wherein Q is as defined above and S and S' are independently lower alkyl, an aryl group containing from 5 to 14 ring atoms, and -(CH2)n- where n=2-4, with an excess amount of a pyrrole in the presence of a catalytic amount of a strong Lewis or Bronsted acid; (b) removing any unreacted pyrrole or other solvents used by evaporation; (c) removing polymeric materials and removing the cor- responding dipyrromethane by-product, leaving the compound of Formula I.