The chlorination, sulphonation, and nitration of pyrrolo[1,2-a]quinoxalines
Abstract
Pyrrolo[1,2-a]quinoxaline undergoes very smooth electrophilic substitution. Chlorination yields mainly 1-chloro-pyrrolo[1,2-a]quinoxaline together with a small amount of a second monochloro-derivative. This is believed to be the 3-chloro-compound on the basis of proton magnetic resonance evidence. Sulphonation apparently occurs exclusively at position 3 and nitration gives an approximately 2 : 1 mixture of the 3- and 1-mononitro-compounds.