Molecular Rearrangement of Pyrazino[2,3- c ]quinolin-5(6 H )-ones during Their Reaction with Isocyanic Acid.

New tetrahydropyrazino[2,3- c ]quinolin-5(6 H )-ones were prepared from 3-chloroquinoline-2,4(1 H ,3 H )-diones and ethylene diamine. In their reaction with HNCO, an unprecedented molecular rearrangement produced new types of hydantoin derivatives. All prepared compounds were characterized on the basis of their 1 H, 13 C, and 15 N NMR and ESI mass spectra and some were authenticated by X-ray analysis of single crystalline material. A proposed mechanism for rearrangement is discussed in this essay. The CDK and ABL inhibition activity as well as in vitro cytotoxicity of the prepared compounds was also tested.