https://translate.google.ru/#view=home&op=translate&sl=en&tl=ru&text=Pyrrole%20is%20a%20five-membered%20aromatic%20heterocyclic%20compound%2C%20which%20contains%20one%20nitrogen%20atom.%20Pyrrole%20is%20a%20colorless%20volatile%20liquid%20that%20darkens%20readily%20upon%20exposure%20to%20air%20and%20is%20usually%20purified%20by%20distillation%20immediately%20before%20use.%20Due%20to%20its%20aromatic%20character%2C%20pyrrole%20is%20difficult%20to%20hydrogenate%2C%20does%20not%20easily%20react%20as%20a%20diene%20in%20Diels%E2%80%93Alder%20reactions%2C%20and%20does%20not%20undergo%20usual%20olefin%20reactions.%20Its%20reactivity%20is%20similar%20to%20that%20of%20benzene%20and%20aniline%2C%20in%20that%20it%20is%20easy%20to%20alkylate%20and%20acylate.%20Under%20acidic%20conditions%2C%20pyrroles%20polymerize%20easily%2C%20and%20thus%20many%20electrophilic%20reagents%20that%20are%20used%20in%20benzene%20chemistry%20are%20not%20applicable%20to%20pyrroles.%20Pyrrole%20and%20its%20derivatives%20(pyrroles)%20are%20widely%20used%20as%20an%20intermediate%20in%20the%20synthesis%20of%20pharmaceuticals%2C%20medicines%2C%20agrochemicals%2C%20dyes%2C%20photographic%20chemicals%2C%20perfumes%2C%20and%20other%20organic%20compounds.%20For%20example%2C%20chlorophyll%20and%20heme%20are%20the%20derivatives%20which%20are%20made%20by%20four%20pyrrole%20ring%20formation%20of%20the%20porphyrin%20ring%20system.%20Pyrrole%20is%20a%20precursor%20to%20the%20nonsteroidal%20anti-inflammatory%20drug%20tolmetin.