Poorly reactive 5-piperazin-1-yl-1,3,4-thiadiazol-2-amines rendered as valid substrates for Groebke–Blackburn type multi-component reaction with aldehydes and isocyanides using TMSCl as a promoter

✍ Scribed by Mikhail Krasavin; Sergey Tsirulnikov; Mikhail Nikulnikov; Volodymyr Kysil; Alexandre Ivachtchenko

• Publisher: Elsevier Science
• Year: 2008
• Tongue: French
• Weight: 165 KB
• Volume: 49
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2008.06.113

✦ Synopsis

N-Substituted 5-piperazin-1-yl-1,3,4-thiadiazol-2-amines that fail to undergo Groebke-Blackburn type MCR with aldehydes and isocyanides provide fair to good yields of the respective 2-piperazin-1-ylimidazo[2,1-b][1,3,4]thiadiazoles when such reaction is promoted by an equimolar quantity of trimethylsilyl chloride in aprotic medium. These findings further extend the utility of TMSCl as the isocyanide-based MCR promoter, and also demonstrate that this silicon Lewis acid is the actual promoter of the reaction.