[¦en ə¦sed·əl·səl′fan·ə·lil ′klȯr‚īd] (organic chemistry) C8H8ClNO3S Thick, light tan prisms ranging to brown powder or fine crystals with a melting point of 149°C; soluble in benzene, chloroform, and ether; used as an intermediate in the preparation of sulfanilamide and its derivatives. Abbreviated ASC.