| 摘要 |
Prepn. of 2-(benzylidene or naphthylidene) acylacetic or malonic acid esters or amides of formula Ar-CH=C(COR<1>)(COR<2>) (I) involves reacting an aromatic aldehyde of formula ArCHO (II) with an active methylene cpd. of formula CH2(COR<1>)(COR<2>) (III). In the formulae, Ar = phenyl or naphthyl (both opt. substd. by 1-3 or 1-4C alkyl, 1-4C alkoxy and OH); R<1> = 1-8C alkoxy, phenoxy, benzyloxy or -NR<3>R<4>; R<3>,R<4> = H or 1-6C alkyl; R<2> = 1-4C alkyl, phenyl, benzyl or as R<1>. The novelty is that the reaction mixt., at the end of the reaction, is washed with aq. alkali metal (hydrogen) sulphite soln. to remove residual, unconverted (II). Pref. the organic solvent in the organic phase obtd. after the (bi)sulphite wash is distilled off to give a technical prod. contg. (I). The use of this technical prod. as brightener is claimed. Preferably, Ar = phenyl (opt. substd. by 1 or 2 of Me, Et, OMe and OEt); R<1> = 1-8C alkoxy; R<2> = 1-4C alkyl or 1-6C alkoxy. Esp. Ar = Ph, R<1> = OMe or OEt, and R<2> = Me, OMe or OEt. |
