Patent GB-767423-A (GB)
Title: C-tricyanovinyl compounds and their preparation
IPC: C07D215/12
Filed: 1954-09-28
Abstract: The invention comprises aromatic compounds containing a tricyanovinyl substituent bonded to a ring carbon atom, and also containing a ring hetero atom or at least one auxochrome substituent bonded to a second ring carbon atom.  Auxochromes specified are amino or substituted amino, hydroxy, alkoxy, halogen, sulpho, sulphoester, carboxy and carbethoxy.  The products are dyes for cellulose acetate, polyacrylonitriles, and polyesters.  The invention also includes processes of preparing C-tricyanovinyl compounds generally by (1) oxidizing a compound containing the a ,b ,b -tricyanoethyl group <FORM:0767423/IV(b)/1> bonded to carbon, where M is hydrogen or a metal, or (2) reacting tetracyanoethylene with (a) a primary aromatic amine having both orthopositions occupied otherwise than by hydrogen or halogen to avoid formation of the N-substituted bodies, (b) a secondary or tertiary aromatic amine having a free para-position, (c) a phenol having a free ortho- or para-position, or (d) an aromatic heterocyclic compound containing a ring nitrogen atom with at least one carbon atom bonded directly to hydrogen, and in which only two bonds of the nitrogen are attached to the ring. Oxidizing agents specified for method (2) are air, oxygen, hydrogen peroxide, benzoyl peroxide, lead tetra-acetate, red lead oxide, calcium hypochlorite, or bromine.  In examples: (1) 4 - tricyanovinyl - N,N - dimethylaniline is obtained by oxidation with lead tetra-acetate or benzoyl peroxide of 4-(a ,b ,b -tricyanoethyl)-N,N-dimethylaniline or its potassium salt and reference is made to similar oxidations of N-methyl - a  - (a ,b ,b  - tricyanoethyl) - pyrrole, N - methyl - a ,a 1 - dimethyl - b  - (a ,b ,b  - tricyanoethyl) pyrrole, 1,1,2 - tricyano - n - butane, and 1,1,2 - tricyano - 3,3 - dimethyl - n - butane; (2) tetracyanoethylene dissolved in tetrahydrofuran is condensed with N-methylaniline, N,N-dimethylaniline, 2,6-dimethylaniline, N-methyl-N-(b -cyanoethyl) aniline, N-butyl-N-(b -cyanoethyl) aniline, tetrahydroquinoline, diphenylamine, N - phenylethanolamine, N - (b  - cyanoethyl) aniline, N - (b  - cyanoethyl) - o - toluidine, 2,6 - dimethylphenol (in presence of pyridine or sodium methoxide), giving the corresponding p-tricyanovinyl bodies.  Also in examples: (3) tetracyanoethylene is condensed in acetone with N-methylpyrrole or with pyrrole itself to give o-tricyanovinyl N-methylpyrrole and o-tricyanovinylpyrrole.  A dyeing example describes the dyeing of cellulose acetate with N,N-dimethyl-4-tricyanovinylaniline.ALSO:The invention comprises aromatic compounds containing a tricyanovinyl substituent bonded to a ring carbon atom, and also containing a ring hetero atom or at least one auxochrome substituent bonded to a second ring carbon atom. Auxochromes specified are amino or substituted amino, hydroxy, alkoxy, halogen, sulpho, sulphoester, carboxy and carbethoxy.  The products are dyes for cellulose acetate, polyacrylonitriles and polyesters.  The invention also includes processes of preparing C-tricyanovinyl compounds generally by (1) oxidizing a compound containing the   b b  - tricyanoethyl group <FORM:0767423/IV(b)/1> bonded to carbon, where M is hydrogen or a metal or (2) reacting tetracyanoethylene with (a) a primary aromatic amine having both ortho-positions occupied otherwise than by hydrogen or halogen to avoid formation of the N-substituted bodies, (b) a secondary or tertiary aromatic amine having a free para-position, (c) a phenol having a free ortho- or para-position, or (d) an aromatic heterocyclic compound containing a ring nitrogen atom with at least one carbon atom bonded directly to hydrogen, and in which only two bonds of the nitrogen are attached to the ring. Oxidizing agents specified for method (2) are air, oxygen, hydrogen peroxide, benzoyl peroxide, lead tetra-acetate, red lead oxide, calcium hypochlorite, or bromine.  In examples, (1) 4-tricyanovinyl-N.N-dimethylaniline is obtained by oxidation with lead tetra-acetate or benzoyl peroxide of 4-(  b b  tricyanoethyl) 4 - (  b b  - tricyanoethyl)-N.N-dimethylaniline or its potassium salt and reference is made to similar oxidations of N - methyl -   - (  b b  - tricyanoethyl) - pyrrole, N-methyl-  1-dimethyl-b  ( b b -tricyanoethyl) pyrrole, 1.1.2-tricyano-n-butane, and 1.1.2-tricyano-3.3-dimethyl-n-butane; (2) tetracyanoethylene dissolved in tetrahydrofuran is condensed with N-methylaniline, N.N-dimethylaniline, 2.6-dimethylaniline, N-methyl-N-(b -cyanoethyl) aniline, N-butyl-N-(b -cyanoethyl) aniline, tetrahydroquinoline, diphenylamine, N-phenylethanolamine, N-(b -cyanoethyl) aniline, N-(b -cyanoethyl)-o-toluidine, 2.6-dimethylphenol (in presence of pyridine or sodium methoxide), giving the corresponding p-tricyanovinyl bodies.  Also in examples (3) tetracyanoethylene is condensed in acetone with N-methylpyrrole or with pyrrole itself to give o-tricyanovinyl N-methylpyrrole and o-tricyanovinylpyrrole.  A dyeing example describes the dyeing of cellulose acetate with N.N-dimethyl-4-tricyanovinylaniline.