9H-Pyrrolo[2,3-b:5,4-c′]dipyridine-6-carbonitrile, 3-bromo-5-chloro-9-(phenylsulfonyl)-

9-(Benzenesulfonyl)-3-bromo-5-chloro-9H-pyrrolo[2,3-b:5,4-c']dipyridine-6-carbonitrile