Benzoquinone dioximates

Benzoquinone, 3,5-di-t-butyl-cobalt complexes, 2, 398 Benzoquinone dioximates metal complexes... 

Any substance which will bring about vulcanisation. Elemental sulphur remains a widely used vulcanising agent, but sulphur-containing substances (such as thiuram disulphides) have important uses. Organic peroxides (benzoyl and dicumyl) and nitroso derivatives (e.g., benzoquinone dioxime) are used in vulcanising certain synthetic elastomers. 

Benzofuroxans are far more stable than simple furoxans and are more favourable for practical applications. There are two standard methods for the synthesis of the benzofuroxan skeleton (1) treating an ortho-nitroarylamine with a mild oxidant like sodium hypochlorite and (2) either heating or irradiating an orf/to-nitroarylazide with UV light. Benzofuroxan itself has also been prepared by treating 1,2-benzoquinone dioxime with alkaline hypochlorite or alkaline potassium ferricyanide solution. ... 

Benzoquinone dioximes and aldehydes in the presence of acidic catalyst (for example, HCIO4) in EtOH afforded 1-hydroxybenzimidazole 3-oxides ". 

Problem 19.33 From phenol prepare (a) p-benzoquinone, (b) p-benzoquinone dioxime, (c) quinhydrone (a 1 1 complex of p-benzoquinone and hydroquinone). 4... 

O.NiCgH2(CH3)2 N.6 ( ) mp 250° diffc sol prepd by heating a soln of 1,4-dlmethyl-benzoquinone-dioxime in NaOH with K ferric cyanide soln (Ref 1, p659 Ref 2)... 

Occupational exposure to 1,4-benzoquinone dioxime probably occurs during its manufacture, its use as a rubber vulcanizing agent and its conversion to chemical derivatives (lARC, 1982). 

Benzoquinone dioxime was tested for carcinogenicity in mice and rats by oral administration in the diet. No significant increase in the number of neoplasms was observed in male rats, but in females in the highest-dose group there was an increase in the number of transitional cell papillomas and carcinomas of the urinary bladder. In mice, no carcinogenic effect was observed (lARC, 1982). 

Benzoquinone dioxime induced mutations in bacteria and in cultured mouse lymphoma L5178Y cells, but not in Drosophila melanogaster. It gave inconclusive results for the frequency of transformed CSH lOT A cells. In female rats treated in vivo,... 

No epidemiological data relevant to the carcinogenicity of 1,4-benzoquinone dioxime were available. 

Table 3 Non-integral Oxidation State Metal Glyoximates and Benzoquinone Dioximates...

Ni(N=CHCMe2CH2NHCH2CH2NHCH2-CH2NHCH2CH2)]21,164 NiC12H10Io 52N404 Ni(benzoquinone dioxime)2I0.52,144 NiC-i II 1 N204S4... 

Pd(benzoquinone dioxime)2,143 PdC,2H CIN202 PdCI(OH)(phen)(H20), 305 PdC12H29ClN3... 

Figure 7 p-Benzoquinone dioxime cross-linking of butyl rubber. (From Ref. 59.)... 

The aldehyde (50 mmol) and -benzoquinone dioxime (6.90 g, 50 mmol) are dissolved in ethanolic hydrochloric acid (3.5 m, 100 ml). The reaction mixture is then refluxed for several hours until the deep red colour disappears. After cooling, the hydrochloride is filtered off, suspended in ethanol (100 ml), water (200 ml) is added, and the mixture is neutralized with aqueous ammonia. The precipitate is filtered, washed in turn with water and ethanol, and dried. Prepared in this way are the following 1-hydroxybenzimidazole 3-oxides (2-substituent, yield, m.p. listed) Ph, 72%, 223-224°C -Me2NC6H4, 91%, 180-185 C -HOC6H4, 65%, 227-228°C ... 

Oximes. The reaction of p-benzoquinone dioxime, HQN=< =NQH, with nitric oxide in basic methanol solution is reported (8) to produce 2O2N— —N202. The sodium salt of n-butylaldoxime, RCH = NONa,... 

NOTE See also Benzoquinone-dioxime and Derivatives in Vol 2 of Encycl, pp B83—B84... 

Benzoselenadiazole-N-oxide (210) was prepared by Pedersen through the reaction of o-benzoquinone dioxime (209) with selenium monochloride [Eq. (50)]. 

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