Nitrodiazo compounds

Anions of polynitro compounds (21) or neutral nitrodiazo compounds (22) can be considered as possible precursors of nitrocarbenes (A B) by analogy with other functionalized carbenes. Nitrocarbenes can react with a double bond... 

It has been expected that trinitromethane derivatives of the general formula (NC>2)3C — M (M is K, Cs, SiMe3, or SnBuj) can generate dinitrocarbene through solvolysis, and the latter can react as a 1,3-dipole with some olefins (74). However, a next study (75) demonstrated that this interpretation of the processes is erroneous at least for M=SiMe3. Attempts to detect nitrocarbenes in cycloaddition reactions during thermolysis or photolysis of aliphatic nitrodiazo compounds also failed (76). 

In addition to conventional generation of carbenes from nitrodiazo compounds (22) (79), target intermediates C can be prepared by oxidation of functionalized AN CH2XNO2 with phenyliodonium diacetate. The reactions of Rhodium intermediates with certain olefins afford the corresponding cyclopropanes (23). The cycloaddition reaction was performed in the presence of a catalyst. (The successful synthesis of nitrocyclopropanes from trinitromethane derivatives and nitroacetic ester was also documented (81)). 

Since o- and p-nitrodiazo compounds are rearranged, even by soda, to the noncoupling isodiazotates, it is desirable to work with these in the absence of soda and to use, instead, sodium acetate, or, in special cases, an acid-binding agent such as calcium carbonate or magnesia, so that the solution is never alkaline. 

These mordant-dyeing properties are found in a much higher degree in the bodies obtained by action of nitrodiazo-compounds on salicylic acid (Germ. Pat. 44170, 16 Nov., 1887). The dyestuff from metanitrodiazobenzene and salicylic acid comes into commerce as Alizarin Yellow G, and produces a fine yellow lake with chromium oxide. The pure dyestuff crystallizes from alcohol in light yellow needles. M.P. about 230°. Its constitution may be expressed by the formula —... 

These compounds are also useful in wool-dyeing. The dyeing process is simple, as owing to the stability of these compounds the mordanting with bichromate and the dyeing may be effected in one bath. -oxynaphthoic acid combines with nitrodiazo-compounds, producing brown dyestuffs which possess the property, like the above, of dyeing on mordants. 

Meldola introduced a general method for preparing disazo-compounds [62]. Nitrodiazo-compounds are combined with... 

The nitroazo-compounds obtained by combination of nitrodiazo-compounds with primary amines may be diazotised and combined with phenols resulting nitrodisazo-compounds on reduction yield amido-compounds, which, when again diazotised and combined with a phenol, yield tertiary azo-compounds, containing three azo-groups. 

Table 1. Nitrocyclopropanes from Nitrodiazo Compounds and Alkenes...

CAUTION Nitrogen dioxide and dinitrogen pentoxide are extremely toxic and hazardous substances. All diazo compounds and particularly nitrodiazo compounds are potentially toxic and explosive. Ni-trodiazoacetic acid and nitrodiazomethane are extremely explosive. A face shield and heavy gloves should be worn when working with these compounds. 

Other alkenes can be cyclopropanated with nitrodiazo compounds in the same manner. Table 1 presents a survey. In the case of cycloadducts with ethyl nitrodiazoacetate, it is even possible to separate the diastereomeric cyclopropanes by partial saponification of the less sterically hindered isomer. ... 

Another application of rhodium carbenoid chemistry relates to the synthesis of strained-ring nitro compounds as high energy-density materials. Nitrocyclo-propanes are the simplest members of this class of compounds and catalyzed additions of a nitrocarbene to an olefin have only been described recently [40], Detailed studies have shown that the success of the reaction is, as expected, dependent on both the alkene and the nitrodiazo precursor. Consistently with the electrophilic character of rhodium carbenoids, only electron-rich alkenes are cyclopropanated. The reaction has been extended to the synthesis of nitrocyclo-propenes but the yields are good for terminal acetylenes only [41]. 

This does not react as a diazo-compound unless a mineral acid is added to the solution. Bamberger called it an isodiazo -compound, which isomerises to a diazo-compound. By the action of hot concentrated potassium hydroxide solution on Griess s diazobenzene potassium (see p. 771), Schraube and Schmidt obtained an isomeric compound giving the diazo-reaction with acid. Von Pechmann and L. Frobenius found that the silver salt of /)-nitrodiazo-benzene with methyl iodide does not give a nitrosamine but the methyl ether CeH4(N02)-N N-0CH3, so that the nitrosamine formula appeared to represent a tautomeric form of diazobenzene. 

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