5,10,15,20-Tetrakis(4-hydroxyphenyl)-21H,23H-porphine

5,10,15,20-(tetra-4-hydroxyphenyl)porphyrin is a porphyrin derivative used for detection of water-soluble vitamins by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry.

109-97-7

123-08-0

51094-17-8

6.1 g of p-hydroxybenzaldehyde was dissolved in 110 mL of propionic acid, 6 mL of dimethyl sulfoxide (DMSO) was added, the mixture was mechanically stirred and heated to 128°C. Freshly distilled 3.5 mL of pyrrole was dissolved in 10 mL of propionic acid and slowly added dropwise at a rate of 1 drop per second to the above reaction mixture. The temperature of the reaction system was then raised to 141 °C and the reaction was refluxed for 2 hours. Upon completion of the reaction, hot filtration was performed and the filter cake was washed twice with propionic acid to obtain a blue solid 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin crude product. 10 g of the dried crude product was placed in a 100 mL round-bottomed flask, 20 mL of anhydrous ethanol was added and heated to reflux for 15 minutes before continuing to heat for 1.5 hours. The reaction solution was cooled in an ice bath for 1.5 h. The reaction solution was filtered and washed twice with ethanol to give 0.6172 g of 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin in 7.27% yield. Finally, the purified product was purified by silica gel column chromatography (200 mesh) using acetone as eluent.