| abstract |
These derivatives correspond to the formula (CF DRAWING IN BOPI) in which X represents an oxygen or sulfur atom, one of Y1 or Y2 represents NR "and the other represents C = X or CH2, Z represents NH or CR'R "; R, R 'and R "each represent a hydrogen atom, an optionally halogenated alkyl or cycloalkyl group, and R1, R2 and R3 each represent a hydrogen atom or a hydroxy, acyloxy, benzoyloxy, N3, SCN or CN group , or the symbols R1 and R2 together represent a second bond, with the proviso that R1, R2 and R3 are not H simultaneously. |