Isocyanide-Based Three-Component Synthesis of Highly Substituted 1,6-Dihydro-6,6-dimethylpyrazine-2,3-dicarbonitrile, 3,4-Dihydrobenzo[g]quinoxalin-2-amine, and 3,4-Dihydro-3,3-dimethyl-quinoxalin-2-amine Derivatives

✍ Scribed by Ahmad Shaabani; Fatemeh Hajishaabanha; Hamid Mofakham; Mojtaba Mahyari; Bagher Lali

• Publisher: John Wiley and Sons
• Year: 2012
• Tongue: German
• Weight: 236 KB
• Volume: 95
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.201100270

✦ Synopsis

Abstract

A novel and efficient isocyanide‐based multicomponent reaction between alkyl or aryl isocyanides 1, 2,3‐diaminomaleonitrile (2), naphthalene‐2,3‐diamines (6) or benzene‐1,2‐diamine (9), and 3‐oxopentanedioic acid (3) or Meldrum's acid (4) or ketones 7 was developed for the ecologic synthesis, at room temperature under mild conditions, of 1,6‐dihydropyrazine‐2,3‐dicarbonitriles 5a–5f in H~2~O without using any catalyst, and of 3,4‐dihydrobenzo[g]quinoxalin‐2‐amine and 3,4‐dihydro‐3,3‐dimethyl‐quinoxalin‐2‐amine derivatives 8a–8g and 10a–10e, respectively, in the presence of a catalytic amount of p‐toluenesulfonic acid (TsOH) in EtOH, in good to excellent yields (Scheme 1).