ISSN:
1434-4475
Keywords:
4,5-Bis-(alkyl,aryl)amino-2-dicyanomethylene-cyclopentene-1,3- dione
;
4,5-Dichloro-2-dicyanomethylene-4-cyclopentene-1,3-dione
;
Dyes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract 4,5-Dichloro-2-dicyanomethylene-4-cyclopenten-1,3-dione (2) is synthesized by partial Retro-Michael addition of tetracyanoethylene to 4,5-dichloro-4-cyclopentene-1,3-dione. Compound2 is a new electron acceptor, withN-methyl-benzthiazolone-2-hydrazone giving a charge-transfer complex (6). Nucleophilic substitution of2 by pyrrolidine, morpholine and piperidine leads to deeply coloured bisamides7,8. With aromatic amines bisamides are formed too (11), but monosubstitution products can be isolated.N,N-Dimethylaniline reacts with2 by elimination of hydrogen chloride, leading to aN,N-dimethylaminophenyl monosubstitution product of2. The bisamides are green-blue compounds with intense violet colour in solution. The dyes can be classified as pseudooxo croconic acid bisamides, the new type of chromophore is discussed by13C-spectroscopy and quantum chemical calculations (CNDO-CI).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00799246
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