Synthese vonN-substituierten Oxo- und Thioxopyrimidinen aus 1,2,4-Dithiazoliumsalzen

✍ Scribed by Holzer, Max ;Dobner, Bodo ;Briel, Detlef

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 630 KB
• Volume: 1994
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.199419940909

✦ Synopsis

Synthesis of N‐Substituted Oxo‐ and Thioxopyrimidines from 1,2,4‐Dithiazolium Salts

2,4‐Diaryl‐substituted 1,3‐thiazine‐5‐carbonitriles 5, 6, obtained by reaction of 1,2,4‐dithiazolium salts 1 with activated cyanoacetates, undergo ring transformations in the presence of primary and secondary amines. Thus, 5 and 6 react with primary amines under mild conditions to give hardly accessible N‐3‐substituted oxopyrimidine‐ or thioxopyrimidine‐5‐carbonitriles 11, 16, with secondary amines to give N‐3‐unsubstituted pyrimidine derivates 14, 19 and with diamines to give imidazo[1,2‐c]pyrimidines or pyrimido[1,2‐c]pyrimidines 23a, b. After alkylation of 1,3‐thiazines 6, highly reactive 1,3‐thiazinium salts 8 can be isolated.