The title compound 4-bromo-5-ethoxy-3-methyl-5-(naphthalen-1-yl)-l-tosyl-IHpyrrol-2(5H)-one 1 (C24H22BrNO4S, M-r = 500.40) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P2(1)/n with a = 8.8562(15), b = 18.118(3), c = 14.055(2) angstrom, beta = 99.855(3)degrees, V = 2221.9(6) angstrom(3), Z = 4, D, = 1.496 g/cm(3), p = 1.975 mm(-1), lambda = 0.71073 angstrom, F(000) 1024, R 0.0607 and wR = 0.1371.