Abstract Novel environment-benign one-pot syntheses of water-soluble porphyrins, trans-dihydroxy-5,10,15,20-tetra(N-methyl-4′-pyridiniumyl)porphyrinate tin(IV) (Sn(IV)TMPyP(OH)2) and water-insoluble trans-dihydroxy-5,10,15,20-tetra(4-pyridyl)porphyrinate tin(IV) (Sn(IV)TPyP(OH)2), were found to proceed in water as solvent at room temperature with high yield (90 and 93%).