Cyclisierungen mit Cyanthioacetamid in Gegenwart von Schwefel

✍ Scribed by Prof. Dr. K. Gewald; Dipl.-Chem. R. Schindler

• Book ID: 105353666
• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 356 KB
• Volume: 332
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/prac.19903320213

✦ Synopsis

Cyclizations of Cyanothioacetamide in the Presence of Sulphur

Cyanothioacetoamide 1 reacts with sulphur in the presence of triethylamine to form the 2,5‐diamino‐thiophene derivative 3 and in the presence of sodium ethoxide the 1,4‐dihydropyridine derivative 2, respectively. 3 easily undergoes ring opening to yield the butadiene derivative 6. Catalyzed by amine from 1, cyclic ketones, and sulphur the 2‐spiro[thieno[2,3‐d]pyrimidine‐4‐thiones] 8 arise. Analogously to other cyanoacetic acid derivatives 1 react with sulphur and isothiocyanates to form the 4‐amino‐Δ^4^‐thiazoline‐2‐thiones 9 and with sulphur and carbon disulfide to yield the 5‐amino‐1,2‐dithiol‐3‐thione derivative 12. Among the o‐amino‐thiocarboxamides 3, 9, 12 the compounds 3 and 9 can be converted into the 5,6‐heterocondensed pyrimidine‐4‐thiones 4 and 10.