申请人:Montedison S.p.A.
公开号:EP0091383A1
公开(公告)日:1983-10-12
The present invention describes a process for the catalytic reduction of nitro-aromatic compounds by transfer of hydrogen from alcohols to nitro-aromatic compounds, said reduction being catalyzed by iridium complexes and characterized in that a primary or secondary alcohol having the formula (I) or a glycol:
is made to react with a nitro-aromatic compound having the formula (II):
wherein:
R and R', possibly linked to each other according to homo- or heterocycles, represent indifferently either a hydrogen atom or a possibly substituted hydrocarbylic group having up to 30 carbon atoms;
Ar represents an aryl or hetero-aryl group, also substituted with inert groups;
x and y, either equal to or different from each other, represent an integer chosen from 1 and 2, in the presence of a complex catalyst of iridium chosen from among those having formulae (III) and (IV):
and
wherein:
Chel represents a kelating bi-toothed nitrogeneous compound;
L-L represents a molecule of a diolefine, preferably not conjugated;
L represents a mono-olefine molecule;
X- represents an anion chosen from among: Cl-, Br-, I-, PF6-, BR4-, ClO4-, B(C6H5)4-, OH-,
wherein R and R' have the significance already given to them;
Y is a halogen, preferably Cl, Br or I; and optionally with a compound chosen from mineral alkaline compounds, at a temperature comprised between about 20°C and the boiling temperature of the reaction mass.
The compounds thus obtained consist of the derivatives of the partial or total hydrogenation of the nitro-aromatic starting compounds constituted by anilines or aryl-amines in general, by the aryl-hydroxyl-amines, by the aryl-hydrazo compounds and by the aryl-azo compounds, and can be used as intermediates for organic syntheses in general, in the field of fine chemistry.
本发明描述了一种通过将氢从醇转移到硝基芳香族化合物而催化还原硝基芳香族化合物的工艺,所述还原由铱络合物催化,其特征在于,具有式(I)的伯醇或仲醇或乙二醇与具有式(II)的硝基芳香族化合物反应:
与具有式(II)的硝基芳香化合物反应:
其中
R 和 R',可根据同环或杂环相互连接,无一例外地代表氢原子或可能被取代的碳原子数不超过 30 个的烃基;
Ar 代表芳基或杂芳基,也可被惰性基团取代;
x和y,彼此相等或不同,代表选自 1 和 2 的整数,在有选自式(III)和(IV)的铱络 合催化剂存在的情况下:
和
其中
Chel 代表酮化双齿硝基化合物;
L-L 代表二烯烃分子,最好不是共轭的;
L 代表单烯烃分子;
X- 代表一种阴离子,选自以下几种阴离子Cl-、Br-、I-、PF6-、BR4-、ClO4-、B(C6H5)4-、OH-、
其中 R 和 R'具有上述含义;
Y 是卤素,最好是 Cl、Br 或 I;可选择与选自矿物碱性化合物的化合物一起,在约 20°C 至反应物沸腾温度之间的温度下进行。
这样得到的化合物是由苯胺或芳基胺、芳基羟基胺、芳基氢氮化合物和芳基偶氮化合物构成的硝基芳香族起始化合物部分或全部氢化的衍生物,可用作精细化工领域一般有机合成的中间体。