Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Pteridines, IXC. Synthesis, Oxidations and Reactions of 6- and 7-Hydroxy-2-thiolumazines Selective Cytotoxicity of Carboxypeptidase-activated Methotrexate ex-Peptides

Pteridines, IXC. Synthesis, Oxidations and Reactions of 6- and 7-Hydroxy-2-thiolumazines... Summary Various 6-(10, 11) and 7-hydroxy-2-thiolumazines (8,9) have been synthesized and oxidations of the thioamide function studied . H20 2 Oxidation of 7-hydroxy-2-thiolumazine (8) in basic medium leads to pteridine-4,7- dione-2-sulfinate (12), which eliminates S02 in anhydrous acids. Oxidative desulfurization of 8 and its 8- methyl derivative 9 proceeds directly in formic acid with H20 2 and m-chloroperbenzoic acid to give 16 and 17 respectively. KMn04 oxidation forms the pteridine-4,7,dione-2-sulfonates (14, 15), which react under hydrolytic conditions to give the corresponding 2-hydroxy derivtives (18, 19) and on displacement with ammonium acetate/ammonia at elevated temperature form the pterin derivatives 20 and 21. 2-Thio-pteridine-4,6-dione (10) oxidizes also to the corresponding 2-sulfonate (22), which could only be isolated after addition of potassium bisulfite in the form of the dipotassium 7,8-dihydropteridine-4,6-dione- 2,7-disulfonate (23) adduct. The newly synthesized compounds have been characterized by elemental analyses, pKa determinations, UVand IH-NMR-spectra. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Pteridines de Gruyter

Pteridines, IXC. Synthesis, Oxidations and Reactions of 6- and 7-Hydroxy-2-thiolumazines Selective Cytotoxicity of Carboxypeptidase-activated Methotrexate ex-Peptides

Pteridines , Volume 1 (1) – Feb 1, 1989

Loading next page...
 
/lp/de-gruyter/pteridines-ixc-synthesis-oxidations-and-reactions-of-6-and-7-hydroxy-2-6z1fUAgn0z

References

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
de Gruyter
Copyright
Copyright © 1989 by the
ISSN
0933-4807
eISSN
2195-4720
DOI
10.1515/pteridines.1989.1.1.57
Publisher site
See Article on Publisher Site

Abstract

Summary Various 6-(10, 11) and 7-hydroxy-2-thiolumazines (8,9) have been synthesized and oxidations of the thioamide function studied . H20 2 Oxidation of 7-hydroxy-2-thiolumazine (8) in basic medium leads to pteridine-4,7- dione-2-sulfinate (12), which eliminates S02 in anhydrous acids. Oxidative desulfurization of 8 and its 8- methyl derivative 9 proceeds directly in formic acid with H20 2 and m-chloroperbenzoic acid to give 16 and 17 respectively. KMn04 oxidation forms the pteridine-4,7,dione-2-sulfonates (14, 15), which react under hydrolytic conditions to give the corresponding 2-hydroxy derivtives (18, 19) and on displacement with ammonium acetate/ammonia at elevated temperature form the pterin derivatives 20 and 21. 2-Thio-pteridine-4,6-dione (10) oxidizes also to the corresponding 2-sulfonate (22), which could only be isolated after addition of potassium bisulfite in the form of the dipotassium 7,8-dihydropteridine-4,6-dione- 2,7-disulfonate (23) adduct. The newly synthesized compounds have been characterized by elemental analyses, pKa determinations, UVand IH-NMR-spectra.

Journal

Pteridinesde Gruyter

Published: Feb 1, 1989

There are no references for this article.