Abstract:

Starting from benzyl ethylacetate (4) and based on the Knorr condensation reaction, 2,4-dimethyl-3-(3-methoxy-3-oxopropyl)-5-benzylcarboxylate-1H-pyrrole (2) and 2,4-dimethyl-3-methoxymethyl-5-benzylcarboxylate-1H-pyrrole (3) were synthesized. In the ether solution of bromine, pyrrole (2) was converted to the corresponding dipyrromethane (7) through self-condensation, while no reaction happened to pyrrole (3). Under the presence of 2 equivalent of Pb(OAC)₄, 80 ^oC, pyrrole (3) was completely consumed. After the subsequent refluxing in the methanol solution of hydrochloride acid, a novel 2-methoxymethyl-3-methylcarboxylate-4-methyl-5-benzylcarboxylate-1H-pyrrole (1) was synthesized in a yield of 82%. Pyrrole (1)，pyrrole(2), pyrrole (3) and dipyrromethane (7) were characterized through NMR, elemental analysis, mass and IR. The construction of pyrrole (1) will be helpful for the further study of the structure-functionality relationship of pyrrole derivatives.

Key words: Knorr Condensation, Pyrrole, Synthesis