Preparation and hydrogenation of schiff's bases

Claim 1

IN THE METHOD OF PREPARING N-PHENYL AND N-NAPHTHYL N''-CYCLOALKYL-P-PHENYLENEDIAMINES BY REACTING THE CORRESPONDING N-SUBSTITUTED P-PHENYLENEDIAMINE WITH A CYCLOALKANONE AND CATALYTICALLY REDUCING THE RESULTING SCHIFF''S BASE, THE COMBINATION OF STEPS WHICH COMPRISES HEATING A REACTION MIXTURE CONSISTING OF ONE MOLECULAR PROPORTION OF A MEMBER OF THE GROUP CONSISTING OF NPHENYL-P-PHENYLENEDIAMINE AND N-NAPHTHYL-P-PHENYLENEDIAMINE, AT LEAST THREE MOLECULAR PROPORTIONS OF CYCLOALKANONE SELECTED FROM THE GROUP CONSISTING OF CYCLOHEXANONE, CYCLOPENTANONE, METHYLCYCLOHEXANONE, 2,4-DIMETHYLCYCLOHEXANEONE, 3,5-DIMETHYLCYCLOHEXANONE AND 2,4,5-TRIMETHYLCYCLOHEXANONE AND AZEOTROPING AGENT SELECTED FROM THE GROUP CONSISTING OF THE AFORESAID CYCLOALKANONES IN EXCESS OF THE ONE MOLECULAR PROPORTION REQUIRED FOR REACTION AND BENZENE, WHILE AZEOTROPICALLY DISTILLING WATER FROM THE REACTION MIXTURE BELOW 150*C., SAID AZEOROPIC DISTILLATION BEING CONTINUED UNTIL SUBSTANTIALLY THE THEORETICAL AMOUNT OF WATER PRODUCED IN THE FORMATION OF THE SCHIFF''S BASE HAS BEEN REMOVED, THEN SUBJECTING THE DRY UNDISTILLED COMPOSITE SCHIFF''S BAST TO THE ACTION OF MOLECULAR HYDROGEN IN THE PRESENCE OF A NICKEL HYDROGENATION CATALYST AND HYDROGENATING THE CARBON-NITROGEN DOUBLE BOND OF THE SCHIFF''S BASE.