We describe in this work a synthetic methodology of the preparation of the ethyl-2-(2,4-dioxochroman-3-ylidenemethyl)amino-3-dimethylaminopropanoate (4) and its further use as a key intermediate to prepare some N-subsituted 3-(aminomethylene)-4-oxocoumarines. All prepared compounds have been fully characterized by mass spectrometry, 1H, 13C and 2D NMR techniques (HMQC HMBC and NOESY).
B. Trimèche, R. Gharbi, A. Romdhane, S. Hammami, S. Attia, Z. Mighri
The occurrence of polymorphism in inclusion complexes and its potential impact upon solid-state properties provides the impetus for gaining a better understanding and control of this phenomenon. We have used the permeable molecular crystals of the tetrakis(1,2-dihydro-2-oxo-5-pyridyl)silane (1) and the tetrakis(1,2-dihydro-2-oxo-5-pyridyl)stannane (2) to show that the exchange of guests is a method, other than crystallization, to form separately and stabilize kinetic inclusion polymorph.
O. Saied, T. Maris, M. Simard, J. Wuest
Porous molecular networks, hydrogen bond, guests exchange, inclusion polymorphism, pseudopolymorphism