1-Chloro-4-nitrobenzoxadiazole 10199-89-0 4-Chloro-7-nitrobenzofurazan 7-Chloro-4-nitrobenzo-2-oxa-1,3-diazole 7-Chloro-4-nitrobenzofurazan Benzofurazan, 4-chloro-7-nitro- NBD chloride NBD-C 1 NSC228140