Maleic anhydride diphenyl

In the case of 1,3-diphenylisoindole (29), Diels-Alder addition with maleic anhydride is readily reversible, and the position of equilibrium is found to be markedly dependent on the solvent. In ether, for example, the expected adduet (117) is formed in 72% yield, whereas in aeetonitrile solution the adduet is almost completely dissociated to its components. Similarly, the addition product (118) of maleic anhydride and l,3-diphenyl-2-methjdi.soindole is found to be completely dissociated on warming in methanol. The Diels-Alder products (119 and 120) formed by the addition of dimethyl acetylene-dicarboxylate and benzyne respectively to 1,3-diphcnylisoindole, show no tendency to revert to starting materials. An attempt to extrude carbethoxynitrene by thermal and photochemical methods from (121), prepared from the adduct (120) by treatment with butyl-lithium followed by ethyl chloroform ate, was unsuccessful. 

Maleic anhydride is a convenient dienophile because of its rapid reaction with most dienes as well as its stability and ease in handling (although it is poisonous). The diene for this reaction, 1,4-diphenyl-1,3-butadiene, is readily prepared by the Wittig reaction with benzyltriphenylphosphonium chloride and cinnamaldehyde (Chapter 11, Section I). 

A lOO-ml round-bottom flask is charged with a mixture of xylene (25 ml), 1,4-diphenyl-1,3-butadiene (2.3 g), and finely powdered maleic anhydride (1.1 g). (Larger quantities may be used if desired as long as the reagents are equimolar.) The flask is... 

Maleamic acid, cyclization of, 293 Maleic anhydride, 59 Maleimido azine, 307 Manganese diacetate catalysts, 71 Mark-Houwink-Sakurada equation, 57 Material safety data sheets (MSDSs), 246 Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS), 385, 388 McGrath, J. E., 327 MDI isomers, 210 MDIs. See Methylene diphenyl diisocyanates (MDIs)... 

The starting material is succinic dialkylester, which is easily obtained from maleic anhydride. Cyclization is accomplished with sodium alcoholate in a high boiling solvent or solvent mixture (such as diphenylether/diphenyl) to afford the succinylosuccinic dialkylester 54 ... 

Ethanolamines Maleic anhydride Methylene diphenyl diisocy. 

In this context, note that the cycloaddition rate of a crown ether-annulated diazo(diphenyl)methane such as 1 with maleic anhydride is ion-selectively retarded in the presence of alkali perchlorates (21). This observation was attributed to a lowering of the HOMO (dipole) level, due to the electron-withdrawing electrostatic effect of the complexed cation. A parallel to the negative Hammett p values for cycloadditions of ring-substituted diazo(diphenyl)methanes with TONE (22) (p = —2.67) and chloranil (23) (p = —1.67) was drawn. 

The cycloaddition of a variety of sulfur heterocycles to alkenes has also been reported. Dibromomaleic anhydride undergoes [ 2 + 2] cycloaddition to thiophen295 and to benzo[b]thiophen.296 The photoaddition of benzo-[(>]thiophen 1,1-dioxides to alkenes also affords cyclobutane derivatives.297 Of particular interest is the addition of 3-acetoxybenzo[6]thiophen (350) to cyclohexene to give the adduct (351), which on treatment with base, undergoes a retro-aldol ring opening to benzo[6]thiepinone (352).298 A mixture of stereoisomeric cyclobutane derivatives were obtained on irradiation of 2,6-diphenyl-4//-thiopyran-4-one 1,1-dioxide in cyclohexene.299 The [ 2 + 2] cycloaddition of sulfolen to maleic anhydride and to maleimide has been reported.300... 

Rafikov et al. [35] describe a correlation between the electron-donating capacity of substituted benzenes and the efficiency of adduct formation with maleic anhydride. This is only valid if similar compounds are compared. The ionization potentials of benzene and toluene are 9.246 and 8.820 eV, respectively the yields of adduct formation are 70% and 30%, respectively. In the series of halogenobenzenes, the ionization potentials are as follows fluorobenzene, 9.195 eV chlorobenzene, 9.080 eV bromobenzene, 9.030 eV the yields of adducts are 7%, 2%, and <1%, respectively. Anisole and diphenyl ether, with ionization potentials of 8.220 and 8.090 eV, respectively, do not give adducts with maleic anhydride. It thus seems that an increase in the electron-donating capacity of the benzene derivative leads to a decrease in the yield of photoadducts. 

Dimethyl-1,3-diphenyl Maleic anhydride, substituted olelins, bicyclic compounds 86, 104, 174, 314,315... 

Dicar bomethoxy-1,3-diphenyl Dimethyl maleate, dibenzoyl-ethylene, maleic anhydride 316... 

Fig. 1.1 A typical entry from Groth s Chemische Kristallographic, (a) Textual description of the dimorphic diphenyl maleic anhydride, (b) Physical data for the stable modification melting at 155 °C. (c) Physical data for the metastable modification melting at 146°C.

Some unusual zwitterionic pyrazines have been prepared by dehydrogenation of 1,4-disubstituted piperazine-2,6-diones. Honzl et al. (476a) prepared theanhydro-2,6-dihydroxy-l, 4-diphenyl-3,5-bis(phenylthio)pyrazinium dihydroxide [s/c] (92) (which yields adducts by dipolar cycloaddition of maleic anhydride or formaldehyde) by the reaction of 1,4-diphenylpiperazine-2,6-dione with benzenesulfonyl chloride in pyridine. Tanaka et al. (476b), from I,4-diphenylpiperazine-2,6-dione with benzoyl chloride, and tosyl chloride in pyridine at reflux, obtained the anhydro - 3 - benzoyl - 2,6 -dihydroxy -1,4 -diphenyl - 5 - (p - toly lthio)pyrazinium dihydroxide [src] (93), together with some of the S-p-tolyl analogue of (92). 

Use Manufacturing of ethylbenzene (for styrene monomer), dodecylbenzene (for detergents), cyclohexane (for nylon), phenol, nitrobenzene (for aniline), maleic anhydride, chlorobenzene, diphenyl, benzene hexachloride, benzene-sulfonic acid, and as a solvent. 

Van Doom developed a water-soluble diphosphine based on 2,3-bis(diphenyl-phosphino)maleic anhydride, which was converted into the biscarboxylic acid 19 with sodium hydroxide (Scheme 3) [28a]. The compound was also described by Tyler and co-workers in 1993 [28b]. 

In contrast, the adduct (41) obtained from singlet oxygen and l,4-diphenyl-3/7-2-benzopyran-3-one (40) is a stable, crystalline solid (Scheme 2) <78JA2564>. Nonetheless, (41) decomposes in boiling benzene giving o-dibenzoylbenzene (43) and phenyl o-benzoylbenzoate (45) in 85% and 5% yield respectively. No luminescence is detected. The major reaction course is decarboxylation to the intermediate o-xylylene peroxide (42), which can be trapped as its Diels-Alder adduct with maleic anhydride. The ester (45) could have arisen directly from (41) by decarbonylation and concomitant... 

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