Ugi reactions with ammonia offer rapid access to a wide range of 5-aminothiazole and oxazole derivatives.
A series of Ugi reactions has been successfully performed using ammonia as the amine component, employing 2,2,2-trifluoroethanol as a non-nucleophilic solvent in order to suppress known side reactions. Utilizing concentrated aqueous ammonia as a convenient source, this approach offered a simple, one-step assembly of Ugi adducts suitable for elaboration into a variety of 5-aminoazole compounds through postcondensation modifications. Free or N-substituted 5-aminothiazoles and 5-(trifluoroacetamido)oxazoles were all prepared by this improved methodology. The scope of the synthetic route developed and application of the different products are discussed.
Thompson
Mark J
MJ
Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK.
Chen
Beining
B
D000081:Acetamides / Q000737:chemistry; D000588:Amines / Q000737:chemistry*; D000641:Ammonia / Q000737:chemistry*; D008956:Models, Chemical; D010080:Oxazoles / Q000138:chemical synthesis* / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013844:Thiazoles / Q000138:chemical synthesis* / Q000737:chemistry; D014269:Trifluoroacetic Acid / Q000737:chemistry; D014270:Trifluoroethanol / Q000737:chemistry
C545902:5-aminothiazole; D000081:Acetamides; D000588:Amines; D010080:Oxazoles; D012997:Solvents; D013844:Thiazoles; D014270:Trifluoroethanol; D000641:Ammonia; D014269:Trifluoroacetic Acid