3-amino-pyridazines intermediates herbicides pharmaceuticals

摘要

(a) Prepn. of cpds. of formula (I): where R4 = H, alkyl, aryl, OH, alkoxy, aralkoxy or amino; R5 = H, lower alkyl or aralkyl, R6 = lower alkyl, aryl or aralkyl, by subjecting cpds. of formula (II): to hydrogenative cleavage in organic solvents in the presence of Ni catalysts at 140-220 deg.C (pref. 299 deg.) and at a pressure of 20-250 (pref. 160) atm. (b) Cpds. of formula (I) where R4 = OH. (I) are biologically active substances or intermediates for biologically active substances such as pharmaceuticals or herbicides.