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New Approaches to the Synthesis of 4‐(2‐Aminophenyl)‐1,3‐dihydro‐2 H ‐imidazol‐2‐ones and 3‐Ureidoindoles and a Study of Their Interconversion
Author(s) -
Klásek Antonín,
Lyčka Antonín,
Holčapek Michal,
Hoza Ignác
Publication year - 2008
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200890040
Subject(s) - chemistry , quinoline , aryl , alkyl , boiling , triphosgene , medicinal chemistry , organic chemistry , phosgene
3‐Alkyl/aryl‐3‐ureido‐1 H ,3 H ‐quinoline‐2,4‐diones ( 2 ) and 3a‐alkyl/aryl‐9b‐hydroxy‐3,3a,5,9b‐tetrahydro‐1 H ‐imidazo[4,5‐ c ]quinoline‐2,4‐diones ( 3 ) react in boiling concentrated HCl to give 5‐alkyl/aryl‐4‐(2‐aminophenyl)‐1,3‐dihydro‐2 H ‐imidazol‐2‐ones ( 6 ). The same compounds were prepared by the same procedure from 2‐alkyl/aryl‐3‐ureido‐1 H ‐indoles ( 4 ), which were obtained from the reaction of 3‐alkyl/aryl‐3‐aminoquinoline‐2,4(1 H ,3 H )‐diones ( 1 ) with 1,3‐diphenylurea or by the transformation of 3a‐alkyl/aryl‐9b‐hydroxy‐3,3a,5,9b‐tetrahydro‐1 H ‐imidazo[4,5‐ c ]quinoline‐2,4‐diones ( 3 ) and 5‐alkyl/aryl‐4‐(2‐aminophenyl)‐1,3‐dihydro‐2 H ‐imidazol‐2‐ones ( 6 ) in boiling AcOH. The latter were converted into 1,3‐bis[2‐(2‐oxo‐2,3‐dihydro‐1 H ‐imidazol‐4‐yl)phenyl]ureas ( 5 ) by treatment with triphosgene. All compounds were characterized by 1 H‐ and 13 C‐NMR and IR spectroscopy, as well as atmospheric pressure chemical‐ionisation mass spectra.