Azines benzalazine

Azines were also examined by Snyder et al. Benzaldehyde azine (benzalazine) with MA in ether saturated with water gave a maleamic acid derivative 21 in a 78% yield. Maleamic acid formation suggests that the rate of azine hydrolysis may be faster than that of MA under these conditions. 

Azines. Aldehydes react w ith h3 drazine to yield azines the reaction cannot usually be arrested at the hydrazone stage. This reaction may be illustrated by the preparation of benzalazine from benzaldehyde ... 

As for cyclopropanation of alkenes with aryldiazomethanes, there seems to be only one report of a successful reaction with a group 9 transition metal catalyst Rh2(OAc)4 promotes phenylcyclopropane formation with phenyldiazomethane, but satisfactory yields are obtained only with vinyl ethers 4S) (Scheme 2). Cis- and trans-stilbene as well as benzalazine represent by-products of these reactions, and Rh2(OAc)4 has to be used in an unusually high concentration because the azine inhibits its catalytic activity. With most monosubstituted alkenes of Scheme 2, a preference for the Z-cyclopropane is observed similarly, -selectivity in cyclopropanation of cyclopentene is found. These selectivities are the exact opposite to those obtained in reactions of ethyl diazoacetate with the same olefins 45). Furthermore, they are temperature-dependent for example, the cisjtrcms ratio for l-ethoxy-2-phenylcyclopropane increases with decreasing temperature. 

Benzol ani I in. See Benzylidene aniline Benzalazine. Same as Banzaldehyde Azine... 

B) Methylhydr azine Sulfate.—Two himdred grams (0.96 mole) of benzalazine, 350 cc. of dry, thiophene-free benzene, and TOO cc. (133 g., r.05 moles) of dimethyl sulfate (Note 3) are mixed in a 3-I. round-bottomed flask, provided with a reflux condenser... 

Oxidathe deavane of azines. Aromatic azines, for example benzalazine (1), are oxidatively cleaved to the parent aldehyde or ketone in high yield when treated with periodic acid at room temperature in glacial acetic acid or N,N-dimethylformamide (I 2 molar ratio of substrate to oxidant). 

Failure of the aryldiazomethane moiety to participate in the reaction is attributed to steric hindrance effects. Pyrolysis of the mixed azine, benzhydrylidene-benzylidene azine afforded (a) benzonitrile, benzhydrylideneimine, phenanthridine and 6-phenylphenanthridine by the free radical pathway and (b) nitrogen and triphenylethylene by participation of an aryldiazomethane intermediate as suggested in the case di benzalazine. 

It has been suggested [47] that 2-benzoylpyridine azine is reduced via the azo and hydrazine derivatives, rather than through the route suggested previously for benzalazine [1]. It would be rather exceptional if a hydrazine were reducible at the same potential as the azine. 

In some cases the radical anions of azines in DMF are stable enough to allow their electron spin resonance (esr) spectra to be obtained. The radical anion of fluorenone azine is thus stable for months in DMF [52,53]. In the absence of a proton donor, the radical anion is reduced to the dianion, which is stable on the time scale of CV. In the presence of a relatively strong proton donor, such as hexafluoro-2-propanol, fluorenone fluorenylhy-drazine is obtained [53] this is analogous to the reduction of benzalazine in aqueous alkaline solution [1]. 

Furthermore, chlorine is readily added to azines, and the corresponding bis-hydrazidoyl chlorides are obtained in good yield (26.73.98 Yot example, from benzalazine (XXX) and chlorine the bis-benzhydrazidoyl chloride XXI is obtained... 

Benex, MA-vinyl acetate copolymer, 440 Benzalaniline, reaction with MA, 219 Benzalazine see Benzaldehyde azine Benzaldehyde, 177, 185... 

Benzalazine and other aromatic azines were also investigated recently by Bezuglyi and Shimanskaya [108] both in aqueous buffered solutions and in methanol with (C2H5)4NI as supporting electrolyte. Unlike the results obtained in [28], not one wave but two waves were obtained with benzalazine at pH 4-7. Only one wave was obtained in alkaline solution (with one exception). 

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