Verfahren zur Herstellung von alpha,beta-Diaminoacrylnitrilen

摘要

An improved process is disclosed for preparing alpha , beta -diaminoacrylnitriles having the general formula (I) R<3>R<2>NC(R<1>)=C(NR<2>R<3>)CN, in which R<1> stands for hydrogen, substituted or non-substituted aliphatic residues with 1 to 30 carbon atoms, cycloaliphatic residues with 3 to 8 ring members or aromatic, heteroaromatic or araliphatic residues with 7 to 12 carbon atoms; R<2> and R<3> are the same or different and stand for hydrogen or an aliphatic residue with 1 to 15 carbon atoms, a cycloaliphatic residue with 3 to 8 ring members or an aromatic, heterocyclic or araliphatic residue with 7 to 12 carbon atoms, or residues R<2> and R<3> may be bound together into a 5- or 6-membered ring that may also carry another heteroatom. In this process, component (A) is reacted with components (B), (C) and (D) in any desired order. (A) is an alpha -dicarbonyl compound having the general formula R<1>COCHO, in which R<1> has the above-said meaning, or a reactive derivative of said carbonyl compound. (B) is a salt of sulphurous acid, sulphur dioxide or a sulphur dioxide-releasing reactive. (C) is an amine having the general formula HNR<2>R<3> or an aliphatic diamine having the general formula R<3>HN-(CH2)n-NHR<3>, in which the alkylene chain may also bear an R<1> substituent having, like R<3>, the above-said meaning and n equals 2 or 3, or derivatives that are converted into amine or diamine in reaction conditions. (D) is liquid or gaseous hydrocyanic acid or a hydrocyanic acid-releasing reactive. The reaction is carried out with at least 3.5 equivalent alkali compounds per mole of component A. The most part of the alkaline compound consists of potassium compounds and at least one alkali equivalent is added as a free alkaline lye, provided that the proportion of potassium equivalents be sufficiently high for all inorganic salts to remain practically completely in solution at the end of the reaction.