| 摘要 |
PURPOSE:To readily obtain high-purity (>=99.9%) piperazines with controlling generation of by-product having a boiling point close to that of the piperazines by carrying out catalytic reduction of the pyrazines with hydrogen in the presence of a hydrogenating catalyst in the coexistence of ammonia. CONSTITUTION:Ammonia preferably in an amount of 5-20wt.% (based on an amount of raw material pyrazines) coexists in the production of piperazines by catalytically reducing pyrazines expressed by the formula (R1 to R4 represent H, 1-6C alkyl, 3-6C cycloalkyl, aryl, benzyl or phenethyl), etc., with hydrogen in the presence of a hydrogenating catalyst (preferably Raney nickel, Raney cobalt or stabilized nickel). |
