申请人:CIBA-GEIGY Corporation
公开号:US05618965A1
公开(公告)日:1997-04-08
Process for preparing a nitrile of the formula (I) ##STR1## in which R.sub.1, R.sub.2 and R.sub.3 are for example hydrogen, halogen, cyano, hydroxyl, carboxyl, alkyl, alkoxy, alkylthio, alkylamino, dialkylamino, aryl, aryloxy, arylthio or arylamino, or R.sub.2 and R.sub.3 together form a substituted or unsubstituted 4-membered carbon bridge, by reacting an aldehyde of the formula (II) ##STR2## with a hydroxylammonium salt followed by dehydration by heating to an elevated temperature, wherein the reaction takes place in the presence of an anhydrous inorganic sulfate and in the absence of diluents from the group consisting of carboxylic acids, strongly polar aprotic solvents, sulfur compounds and heteroaromatic basic nitrogen compounds. The nitriles obtainable by the process of the invention are valuable intermediates for, in particular, the preparation of diketopyrrolopyrrole pigments.
制备式(I)的腈的过程,其中R1,R2和R3例如是氢,卤素,氰基,羟基,羧基,烷基,烷氧基,烷硫基,烷基氨基,双烷基氨基,芳基,芳氧基,芳硫基或芳基氨基,或R2和R3共同形成取代或未取代的4元碳桥,通过将式(II)的醛与羟胺盐反应,然后通过加热至高温脱水,其中反应在无水无机硫酸盐存在下进行,且无羧酸,强极性无水溶剂,硫化合物和杂环芳基碱性氮化合物的稀释剂。本发明所得到的腈是有价值的中间体,特别是用于制备二酮吡咯吡咯染料。