C 2121 (OTTO) 1-Chloro naphthalene, 99% Cas 90-13-1 - used as solvent additive in the fabrication of fullerene based photovoltaic devices. C 2121 (OTTO) 1-Chloro naphthalene, 99% Cas 90-13-1 used in the synthesis of biologically active compounds in vitro such as aryl chlorides.