Chlorinated Intermediates Clear, colourless to slightly yellow, skin irritating liquid with a pungent Odour • Building block for heterocycles (e.g. furanes, thiazoles, thiophenes, 1,2,3-thiadizoles, pyranes, 1,3,5-triazines) • Building block for amino acids (Cysteine, Serine) • Building block for the synthesis of pharmaceuticals (e.g. Sulfathiazole, Sulfamethoxydiazine, Tolmetin etc.) • Building block for pesticides (e.g. Fenfuram, Thidiazuron) • For synthesis of dyes.