Maleic dinitrile

A stronger donor, the butadiene with the amino groups in place of the methoxy group in the 1,4-positions, was calculated to react with TCNE via a zwitterion (pseudoexcitation band in Scheme 7) [34], The loss of the stereochemical integrity was observed inthe[4+2]cycloadditionreactionsbetweensomestrongdonors,l,4-bis(dimethylamino) butadienes, and acceptors, fumaric and maleic dinitriles [36],... 

Fumaric and maleic dinitriles react similarly, but the 4,5-dicyanotriazolines formed in situ lose a molecule of hydrogen cyanide and give a triazole with the... 

Magnetic field effects. 331 Magnetic moment, 77, 331-32, 385 z component. 161-63 p and ft" contributions, 164-65, 170 excited stale. 158-59 Magnetic optical rotary dispersion (MORD), 142 Maleic anhydride, 420 Maleic dinitrile. 434 Maleimide. 420... 

The synthesis of dithienyl photochromes containing a maleic anhydride fragment (a furan-2,5-dione fragment) as the ethene bridge was a difficult problem. Initially, vicinal dinitriles 160 and 162 were used as the starting compounds (Scheme 49). But the latter compounds give a maleic anhydride only in the cis conformations. The separation of the cis and trans isomers is an additional time-consuming laborious problem. 

The synthesis of l,2-bis(thiophen-3-yl)maleic anhydride involves the dimerisation of a 3-cyanomethyl derivative of thiophene (1.45) by reaction with aqueous NaOH in the presence of CCl. Alkaline hydrolysis of the dinitrile (1.46) and dehydration produces the anhydride (1.47) as shown in Figure 1.12. ... 

An alternative mechanism may include first an O-inserhon step, followed by the transformation of the oxidized compound into the cyano-containing compound. An example might be the oxidation of butadiene to maleic anhydride followed by hydrolysis to the acid, the formation of the diamide and the oxydehydrogenation to the dinitrile. 

Keywords solid-solid reaction, Diels-Alder reactions, maleic anhydride, fumaro-dinitrile, fumarodinitrile, fulvenes, orthoquinone, 9-methylanthracene, ball mill, stereospecific, stereospecific... 

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