Synthesis for β-meso quadruply fused porphyrins

A one pot synthetic strategy for β-meso quadruply fused porphyrins is attempted. For the first time Pictet Spengler reaction was employed for macrocyclization deviating from classical approach of post synthetic modification of porphyrin framework. The monomers were designed in a way that facilitated macrocylization and peripheral fusion simultaneously. Metal templated synthetic approach was utilized to stabilize macrocyclic framework. The macrocycle was purified by scavenging the impurities and did not require column chromatographic separation. This was due to the presence of imine bonds in the periphery that allowed for selective precipitation of porphyrin by protonation. The low yield of macrocycle was rationalized on the basis of strain accumulation during macrocyclization.