Study On Synthesis Of Water Soluble Amino And Sulfonato Substituted Tetraphenylporphyrin

The water-soluble porphyrins play an important role in medicine, molecule identification, analytical chemistry, electrochemistry and photochemistry. But, They were difficult to be prepared in large scale by loading Adler method, Lindsey method or Guo method because of its low yield, also it was very difficult to be separated from the reaction mixture due to its good water-solubility, which limited their application. Synthesis and application studies of functional porphyrin molecules is one of our academic items in our lab. Highly pure functionalized water-soluble porphyrins have been urgently needed. In this researching, synthesis of water-soluble amino-porphyrins and sulfonato-porphyrins has been investigated along with the suitable method for separation and purification of them from the reaction mixture. Based on our modified synthetic methodology, the asymmetric nitro-porphyrin, amino-porphyrin, sulfonato-porphyrin and amino-sulfonato-porphyrin were synthe-sized shown in detail as follows. A.4-Sulfonato-porphyrin and 5-(4-aminophenyl)-10,15,20-tris(4-sulfonato-phenyl)-porphyrin were synthesized by sulfonation of tetraphenylporpyrin and 5-(4-amino phenyl)-10,15, 20-triphenylporphyrin, respectively. After screening the reaction factors, till now the optimum condition of sulfonation is at 120℃ for 4 hs. Sulfonato-porphyrins are poor soluble in the low polar solution, but good soluble in the strongly polar solutions, based on which, the pure sulfonato-porphyrin was obtained in methonal–acetone system successfully. This purification method is very simply and the products obtained by this method is analytically pure. The over all yield could be up to 60%, which is better than the reported yield in literature(15 %). Combined with the synthetic method and purification method developed in this thesis,we successfully got a good methord for synthesis and separation of sulfonato-porphyrin. B.The asymmetrical amino-porphyrin can be prepared by the modified Adler method or via reduction of nitro-porphyrin. The yield of amino-porphyrin from the reduction of nitro-porphyrin was far higher than that from condensating aldehyde with pyrrole. Therefore, we utilize the reduction of nitro-porphyrin after somewhat modification to prepare asymmetrical amino-porphyrin. When the reaction was carried out in the N2 atmosphere, the yield was improved. Also saved stannic chloride(II) and shortened the reactive time. C.The assymmetrical nitro-porphyrin was synthesized by the Adler method with low yield. We changed to nitration of porphyrin with HNO3. Mononitro-porphyrin (60%) and dinitro-porphyrin (52%) were prepared by this method respectively. A series of conditions focus on the solvent and the loaded dosage of HNO3 which affect the nitration of tetraphenylporphyrin were investigated. The results showed that the optimum condition for synthesis of mononitro-porphyrin was at 0-5℃in CHCl3 with n(HNO3)/n(TPP)=17:1 . For dinitro-porphyrin, the optimum condition was at room temperature in CH3COOH. The dinitro-porphyrin has two kind of isomers prepared from tetraphenylporpyrin via nitration. We found that n(cis-dinitro-porphyrin):n(trans-dinitro-porphyrin) is 3.6:1, which was deviated from the theory valve that the molar ratio of them is 2:1. The reasons for the deviation were interpreted reasonably. D.The differences of the data from Uv-vis and 1HNMR of synthesized porphyrin were explained reasonably.