3,5-Pyrazolidinedione, 4-butyl-1,2-diphenyl-, mixed with 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-2-phenyl-3H-pyrazol-3-one 8064-79-7 Irgapyrin Irgapyrine Pabialgin Rheopyrine Wofapyrin