Tetracyanoethylene, condensation with

Tetracyanoethylene, condensation with malonitrile, 41, 99 Tetradecanedioic acid, 43, 39... 

With tetracyanoethylene the 1-methyl derivative of 63 (R = H) led to compounds of type 226 with diethyl azodicarboxylate, to compounds of type 226 and with diethyl azodicarboxylate, to compounds of type 227.114 The 3-formyl and the 3-aminomethylene group of the pyrido[l,2-a] pyrimidines (222 R = H and 224) underwent condensation with compounds containing an active methylene group.297-299,303 The 3-formyl group has also been reacted with primary amines,285 hydrazines.98,260,285 semicarbazide and thosemicarbazide.98... 

Tricyanovinyl-N,N-dimethylaniline has been prepared by adding hydrogen cyanide to -dimethylaminobenzalmalono-nitrile and oxidizing the adduct.3 The present procedure, an adaptation of one that has been published,3 is the more convenient preparative method. It can be applied to a wide variety of secondary and tertiary aromatic amines to give />-tricyanovinyl-arylamines that, like the present one, are dyes.3 Other types of aromatic compounds also condense with tetracyanoethylene in this manner. Thus one can obtain 4-tricyano vinyl-2,6-dimethyl-phenol from 2,6-dimethylphenol, 2-tricyanovinylpyrrole from pyrrole, and 9-tricyanovinylphenanthrene from phenanthrene.4... 

Acceptors. Most common acceptor molecules such as tetracyanoethylene or tetracyanoqurno dime thane ate commercially available. However, TCNQ can be synthesized in high yield by a two-step synthesis involving a condensation of malonitrile with 1,4-cyclohexanedione followed by treatment with an oxidizing agent such as bromine or A-bromosuccinamide in pyridine solvent (23) (Fig. 6). 

Condensation, of paraldehyde with diethyl malonate, 32, 54 of a-phene thyl chloride with diphenylacetonitrile, 39, 74 of phenylacetylene with ethyl orthoformate, 39, 59 of 1-phenylbiguanide with ethyl chloroacetate, 38,1 of potassium diphenylacetonitrile with benzyl chloride, 39, 73 of potassium trithiocarbonate with potassium chloroacetate, 39, 77 of sodium acetylacetonate to tetraacetylethane, 39, 61 of sodium formylacetone with cyano-acetamide, 32, 32 of tetracyanoethylene with N,N-dimethylaniline, 39, 68 of thiophene, paraldehyde, and hydrogen chloride, 38, 86 of thiourea with furfuryl alcohol, 36,66... 

B. Tetracyanoethylene. A mixture of 254 g. (0.25 mole) of the dibromomalononitrile-potassium bromide salt and 1 1. of dry benzene is placed in a 2-1. three-necked flask fitted with a sealed mechanical stirrer and a reflux condenser. The stirrer is started (Note 6), and 100 g. (1.57 g.-atoms) of precipitated copper powder (Note 7) is added. The mixture is heated at reflux with constant stirring for 10-16 hours. The benzene layer becomes progressively deeper yellow as the reaction proceeds. At the end of the reaction period, the hot mixture is filtered by gravity, using a fluted paper. Most of the heavy solid is easily retained in the flask and is heated under reflux with 300 ml. of dry benzene, with stirring, for 30 minutes. Filtration of the hot mixture is carried out as before. Two 25-ml. portions of hot benzene are used to wash the precipitate and are decanted through the filter. 

Mol. wt. 204.18, m.p. 296°. The reagent was prepared by condensation of cyclohexane-1,4-dione with malononitrile, bromination, and dehydrobromination with pyridine. The compound has properties similar to those of tetracyanoethylene and is a TT-acid of comparable strength. The equilibrium constant for ir-complex formation with pyrene is 78.4 as compared to 29.5 for the tetracyanoethylene-pyreno complex. 

Mol. wt, 351,23, m.p. 266-268°, The reagent is prepared in high yield by the condensation of 2,4,7-trinitrofluorenone with malononitrile with piperidine as catalyst, It is intermediate in rr-acid strength between tetracyanoethylene and 2,4,7-trinitrofluorenone,... 

Amino-3,4-dicyano-l-t-butyl-12, 2,6-thiadiazine (266) is prepared in almost quantitative yield (95%) by condensation of t-butylsulfinimidamide (265) with tetracyanoethylene (Equation (36)) <92ZAAC(615)49>. 

A. Z. Djumanazarova, V. P. Litvinov and A. Konar, Charge-transfer complexes of some 5-membered condensed heteroaromatic systems with tetracyanoethylene, Chem. Scr, 20, 214-218 (1982). 

Condensation of addehydes with N-acyl-V -alkylhydrazines affords an incipient azomethineimine capable of cycloaddition to suitable double bonds. The value of the synthesis is indicated by reactions in Scheme 16. Reaction with benzaldehyde shows a marked regioselectivity. Other interesting dipolar additions are shown in Scheme 17. The interm iacy of a diazacyclopenta-dienone in the decomposition of (59) is clearly shown by the trapping experiments. Also reported are adducts of tetracyanoethylene with 3,6-dialkyl-azepines and the Cope rearrangement of the pyrroline oxide (60) to give... 

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