Premium
Preparation, proton and carbon‐13 structure determination, and fungicidal activity of chlorinated 1‐arylamino‐1 H ‐pyrrole‐2,5‐diones
Author(s) -
Yaroslavskym Carmela,
Bracha Peretz,
Glaser Robert
Publication year - 1989
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570260626
Subject(s) - chemistry , pyrrole , pyridazine , maleic anhydride , isomerization , moiety , ring (chemistry) , medicinal chemistry , molecule , organic chemistry , catalysis , copolymer , polymer
1‐(2′,4′‐dichloro)phenylamino‐1 H ‐pyrrole‐2,5‐dione and 1‐(2′,4′,6′‐trichloro)phenylamino‐1 H ‐pyrrole‐2,5‐dione were prepared via direct chlorination of 2‐phenyl‐3‐oxo‐6‐hydroxy‐2 H ‐pyridazine. Both pmr and mass spectroscopy clearly showed that dichloro substitution occurred in the aromatic moiety and not in the vinylic region of the molecule. The former method showed that pyridiazine‐ to pyrrole‐ring isomerization had occurred already at the level of dichlorination. The identical 2′,4′‐dichlorophenyl and 2′,4′,6′‐trichlorophenylpyr‐rolediones were also prepared by reaction of maleic anhydride with the appropriate arylhydrazine. Similar 2′,4‐dichlorophenyl and 2′,4′,6′‐trichlorophenyl analogues were prepared using dichloromaleic anhydride. Cmr spectroscopic techniques were used for pyridazine‐/pyrrole‐ring stereochemical assignment of products derived from dichloromaleic anhydride. 1‐(2′,4′‐dichloro)phenylamino‐1 H ‐pyrrole‐2,5‐dione and the trichloro‐phenyl analogue were shown to exhibit fungicidal activity in both in‐vivo and in‐vitro assays.