1H-Pyrrole-2-carboxylic acid,1-methyl-4-[[[1-methyl-4-[[[1-methyl-4-[[[1-methyl-4-[[(1-methyl-1H-pyrrol-2-yl)carbonyl]amino]-1H-pyrrol-2-yl]carbonyl]amino]-1H-pyrrol-2-yl]carbonyl]amino]-1H-pyrrol-2-yl]carbonyl]amino]-, methyl ester