Tony Porphin Monomer 2 - Bromo-5 - Formyl -3 - Methyl Pyrrole Synthesis And Process Research

Tolyporohin is a kind of nature cyclic tetrapyrroles with manifold bio-functions and has unique optical character in anti-cancer, which represents the future of second generation of photosensitizers. 2-Bromo-5-formyl -3-methylpyrrole is an important intermediate of tolyporohin. On the base of introducing the present research and development of tolyporohin and pyrroles ramification at home and abroad, an emphasis was made on synthesis of 2-Bromo-5-formyl -3-methylpyrrole and the technical conditions of all steps, which was described as follows.Diethyl 3,5-dimethylpyrrole-2,4-dicarboxylate was made by nitrification, reduction and cycle of ethyl acetoacetate. Controlling the reaction condition, 2,4-dicarbethoxy-5-formyl-3-methylpyrrole was made by the selective oxidation of the 5-methyl of the product of first step with Ceric ammonium nitrate. Then 3-ethoxycarbonyl-5-Carboxy-2-formyl-4-methyl pyrrole was made by selective hydrolysis of the product of the second step. Next, 2-Bromo-4-ethoxycarbonyl-5-formyl-3-methylpyrrole was synthesized by replacing the 2-carboxyl with bromine. Finally, 2-Bromo-5-formyl -3-methylpyrrole was prepared by refluence under the alkaline condition.The structures of the synthetic products were characterized by elemental analysis, ultraviolet, infrared, gas mass and ~1H nuclear magnetic resonance. The results came to the following conclusions: the structures and performance indexes of the products conformed to the design requirement, the synthesis way of the target compounds were brief and had good selectivity.