Dibenzo[b,e][1,4]diazepin-1-ones and their Ring-Opened Derivatives: Revisited Synthesis, 2D NMR and Crystal StructureThanks are due to University of Aveiro and FCT/MEC for financial support to the QOPNA research project (FCT UID/QUI/00062/2013) and to the CICECO-Aveiro Institute of Materials (POCI-01-0145-FEDER-007679; FCT UID/CTM/50011/2013), financed by national funds and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement, and to the Portuguese NMR Network. We would like also to thank FCT/MEC and the General Directorate for Scientific Research and Technological Development – DGRSDT of Algeria and Agence Thématique de Recherche en Sciences et Technologie ATRST for approving the co-financed bilateral project PT-DZ/0005. We further wish to thank CICECO for funding the purchase of the single-crystal X-ray diffractometers.
Received: 02 May 2017
Accepted after revision: 21 May 2017
13 July 2017 (eFirst)
The synthesis of 2,3,4,5,10,11-hexahydro-1H-dibenzo[b,e][1,4]diazepin-1-ones was revisited and a catalyst-free method was established, by exploring the reactivity of 3-[(2-aminoaryl)amino]dimedones towards carbonylated electrophiles. 2D NMR and single-crystal X-ray diffraction studies were used to characterize the structures unequivocally and to review the mechanism leading to the formation of supposed positional isomers. The action of 3-[(2-aminoaryl)amino]dimedones on chromene-3-carboxylic acid, fumaryl, and oxalyl chloride has led to dibenzo[b,e][1,4]diazepin-1-one ring opening to produce novel Z-configured enaminone and linear diamides.