An expeditious, solvent-free synthesis ofmeso-arylporphyrins using activated charcoal as a catalyst

Activated charcoal treated with nitric acid was used as a solid catalyst for synthesis of meso-arylporphyrins by condensation of pyrrole with convenient arylaldehydes in a solvent-free system. The reaction took place at 200°C and porphyrins were obtained in good yields. This environment-friendly method avoids the use of detrimental solvents and toxic catalysts.