| 摘要 |
<p>Chromogenic couplers, comprising one or two 5-pyrazolone radicals, at least one of which is 3-amino substd., are prepd. by the acid catalysed reaction between pref. equimolecular amts. of (a) an intermediate coupler as above but 3-alkoxy substd. and (b) a primary amine, or a secondary amine whose N atom forms part of =6 membered sat. heterocyclic. The acid catalyst has a pKa 10.2. The prod. has gen. formfula:- where R is H, alkyl, aryl or heterocyclic, R' is H or forms a 4-6 membered heterocyclic with NR2, R2 is alkyl, aryl, heterocyclic or forms a 5 - 6 membered heterocyclic with NR' and R3 is H, Cl, F, S, SCN, alkoxy, acyloxy, aryloxy etc. or is another 5-pyrazolone ring. Specif. used in colour film developers.</p> |
