Reactive dyes of the formula ##STR1## in which Y is hydrogen or sulfo, U is --CN, --CONH.sub.2, --SO.sub.3 H, --OH or --OSO.sub.3 H, D is a phenyl or naphthyl radical, which can be substituted by C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, halogen, carboxyl and sulfo, and which contains at least one reactive radical bound direclty or via a bridge member to a ring carbon atom, or to which a further radical is bound which contains a reactive radical, and u is the number 2, 3, 4 or 5, are suitable in particular for the dyeing or printing of cellulose-containing fiber materials by the exhaust method or by the continuous method and product in combination with a high colorisitc yield dyeings and prints which have good fastness properties.