Expedious and practical synthesis of the bioactive alkaloids rutaecarpine, euxylophoricine A, deoxyvasicinone and their heterocyclic homologues

• Published in: Tetrahedron letters Vol. 47; no. 11; pp. 1777 - 1781
• Main Authors: Hamid, Abdulkareem, Elomri, Abdelhakim, Daïch, Adam
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 13.03.2006; Elsevier
• Subjects: Alkaloid; Bioactive product; Catalysis; Chemical Sciences; Chemistry; Chemistry, Organic; Heterocycle; Imino-thioether; Lawesson’s; Medicinal Chemistry; One-pot procedure; Organic chemistry; Peptedic coupling; Physical Sciences; Science & Technology; Thioether; Thionation; Thioether; Alkaloid; Thionation; One-pot procedure; Peptedic coupling; Imino-thioether; Lawesson’s; Heterocycle; Bioactive product; one-pot procedure; thionation; imino-thioether; IMINOKETENE CYCLOADDITION; NITROGEN BRIDGEHEAD COMPOUNDS; alkaloid; heterocycle; Lawesson's; RUTECARPINE; bioactive product; peptedic coupling; FACILE TOTAL-SYNTHESIS; thioether; CONDENSATION; DERIVATIVES
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2006.01.031

Fused pyrimido-β-carbolines including rutaecarpine, euxylophoricine A, and deoxyvasicinone were synthesized efficiently from cyclic imino-thioethers and aromatic amino acids or the corresponding amino esters in a one-pot procedure. Efficient assembly of pyrimido-β-carbolines 1 and 2 , including the bioactive alkaloids rutaecarpine, euxylophoricine A, and deoxyvasicinone ( 3 ), is reported from suitable aromatic amino acids 7 or corresponding aromatic amino esters 8 and imino-thioethers 5 or 6 in a one-step sequence in moderate to good yields. The key step of this methodology is based on an intramolecular aza-displacement of a methylthio group followed by spontaneous cyclodehydration. Furthermore, when aromatic amino esters 8 were used instead of amino acids, a tandem amino-methylthio displacement/amino ester cyclization takes place.