Download PDF
Synfacts 2010(5): 0527-0527  
DOI: 10.1055/s-0029-1219719
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart ˙ New York

Tandem Conjugate Addition-Cyclization Synthesis of 1,5-Benzodiazepines

Contributor(s): Victor Snieckus, Toni Rantanen
J. Li, S. Li, C. Li, Y. Liu, X. Jia*
Shanghai University and Shanghai Institute of Organic Chemistry, P. R. of China
Further Information

Publication History

Publication Date:
22 April 2010 (online)

    Permissions and Reprints

Significance

Reported is the synthesis of 1,5-benzodiazepines by the reaction of readily available phenylenediamines with ethyl propiolate. The process is very simple and metal-free, involving refluxing the starting materials in methanol for the requisite time. Different solvents were tested, with methylene chloride and ethanol affording similar yields but requiring longer reaction times. The overall yields were mostly very good, but unsymmetrical diamines afforded mixtures of regioisomers. The substrate scope was also poorly studied in terms of the propiolate reactant.