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Pteridines. Part XLII . Synthesis and properties of 8‐substituted 2,4‐dithiolumazines
Author(s) -
Hübsch Walter,
Jibril Ibrahim,
Huttner Gottfried,
Pfleiderer Wolfgang
Publication year - 1989
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.19890720415
Subject(s) - chemistry , intramolecular force , pteridine , adduct , benzil , diacetyl , tautomer , stereochemistry , methylation , medicinal chemistry , organic chemistry , dna , biochemistry , enzyme , catalysis
Condensation reactions of the 5‐amino‐6‐(subst. amino)‐2,4‐dithiouracils 12 and 13 with diacetyl or benzil led to the 6,7,8‐trisubstituted 2,4‐dithiolumazines 14 – 16 . Methylation of these compounds affected both thio functions forming various types of 2,4‐bis(methylthio)lumazine derivatives depending on the nature of the substituents at C (7) and N(8). The 6,7,8‐trimethyl‐2,4‐dithiolumazine ( 14 ) was converted into 7,8‐dihydro‐6,8‐dimethyl–7‐methylidene‐2,4‐bis(methylthio)pteridine ( 17 ), whereas the 8‐methyl‐6,7‐diphenyl‐(15) and the 8‐(2‐hydroxyethyl)‐6,7‐diphenyl‐2,4‐dithiolumazine ( 16 ) yielded the corresponding covalent inter‐ or intramolecular 7,8‐adducts 18 – 21 . The unusual structures were proven by spectroscopic means and those of the alcohol adducts 20 and 21 , furthermore, confirmed by X‐ray analysis.