Pteridine. Teil LXXXII. Synthese und Reaktivität von Lumazin-7-sulfensäuren

✍ Scribed by Armin Heckel; Wolfgang Pfleiderer

• Publisher: John Wiley and Sons
• Year: 1986
• Tongue: German
• Weight: 735 KB
• Volume: 69
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19860690517

✦ Synopsis

Synthesis and Reactivity of Lumazine-7-sulfenic Acids

The chemical synthesis of the pteridine-7-sulfenic acids 1%16 is described (Scheme I ) . The 1,2,3,4-tetrahydro-1,3,6-trimethyl-2,4-dioxopteridine-7-sulfnic acid (14) was isolated as a stable crystalline solid. Its chemical reactivity was investigated and the physical properties determined. In the solid state, the S-oxide form 14A predominates, but in protic solvents the S-OH tautomer 14 exists most likely. In basic medium, the pteridine-7-sulfenate species is stable, whereas a low pH gives rise to a disproportionation to the disulfide 10 and the corresponding pteridine-7-sulfinic acid 37 (Scheme 4 ) . Reaction of 14 with ethyl propiolate leads, under cis-addition, to 36, oxidation with KMnO, forms 1,2,3,4-tetrahydro-l,3,6-trimethyl-2,4-dioxopteridine-7-sulfonic acid (38) and NaBH, reduction the corresponding 7-mercaptopteridine dione 18(Scheme 4 ) .