Isoindole 1-phenyl

Benzodiazepinones also undergo rearrangement to isoindoles when treated with acetic anhydride and pyridine (Py). The diazepinone (81), for instance, gives l-phenyl-3-acetylisoindole (82) under these conditions. The structure of the product was established in this case by comparison with (82) prepared by acetylation of 1-phenyl-isoindole. The rearrangement may be formally represented by a... 

Two independent molecular orbital calculations (HMO method) of delocalization energies for isoindole and isoindolenine tautomers agree that the isoindole form should possess the more resonance stabilization. The actual difference calculated for isoindole-isoindolenine is about 8 kcal/mole, but increases in favor of the isoindole with phenyl substitution at position 1 (Table VI).Since isoindole and isoindolenine tautomers have roughly comparable thermodynamic stabilities, the tautomeric proce.ss is readily obser-... 

A study of the electrochemical oxidation and reduction of certain isoindoles (and isobenzofurans) has been made, using cyclic voltammetry. The reduction wave was found to be twice the height of the oxidation wave, and conventional polarography confirmed that reduction involved a two-electron transfer. Peak potential measurements and electrochemiluminescence intensities (see Section IV, E) are consistent vidth cation radicals as intermediates. The relatively long lifetime of these intermediates is attributed to steric shielding by the phenyl groups rather than electron delocalization (Table VIII). 

Benz[/]isoindole (125), recently prepared from the p-toluene-sulfonyl derivative (124), proved to be too unstable for isolation, but eould be trapped in solution as the Diels-Alder adduct (127). The corresponding 1-phenyl derivative (126) was also prepared and, aecording to spectral measurements, reacts with maleic anhydride to give the product (128) derived by additive substitution. This subsequently rearranged to the adduct (129). The same behavior is observed in the reaction of (126) with V-phenylmaleimide. This provides the first clear indication that substitution products from isoindole derivatives and dienophiles can be converted into the normal addition products. 

Chemical Name 2-Ethyl-2,3-dihydro-3-[ [4-[2-(1 -piperidinyDethoxy ] phenyl] -amino] -1 H-isoindol-1-one... 

AZIRIDINE, trans-l-ammo-2,3-diphenyl-[1-Azindinamme, trans-(i)-2,3-di-phenyl-], 55,53, 114 AZIRIDINE, frans-2,3-diphenyl-l-phthal-linido- [ l//-Isoindole-l,3(2//)-dione, trans-( )-2-(2,3-diphenyl-1 -azindin-yl) 1,55, 115... 

Photolysis, apparatus for, 55, 17 Phthalimide, N-amino- [ 1//-Isoindole-1,3-(2//)-dione, 2-amino-, 55, 115 Potassium rew-butoxide [2-Propanol, 2-methyl-, potassium salt], 55,12, 13 Potassium iodide, 55, 71 Potassium permanganate [Permanganic acid, potassium salt], 55,68 Propane, 2,2 dimethyl 1 phenyl, 55, 112 Propane, 2 isocyano-2-methyl-, 55, 96... 

Isocyanide, benzyl, 55, 98 Isocyanide, butyl-, 55, 98 Isocyanide, cyclohexyl-, 55, 98 ISOCYANIDE, 1,1-dimethylethyl- [Isocy-amde, tert-butyl-], 55,96 Isocyanide, dodecanyl- 55,98 Isocyanide, ethyl- 55,98 Isocyanide, methyl-, 55, 98 Isocyanide, phenyl-, 55, 98 1//Isoindole 1,3(2//) dione, 2 amino [Phthahmidc, N-amino-], 55, 115 1//-ISOINDOLE-1,3(2//)-DIONE, trans-( )-2-(2,3-diphenyl-l-aziridinvl)-[Azindine, frans-2,3-diphenyl-l-phthalimido-], 55, 115 ISOXAZOLE, 3-(4-chlorophenyl)-5-(4-methoxy phenyl)-, 55, 39 Isoxazole 5-(4-chlorophenyl)-3-(4-meth-oxyphenyl)-, 55, 42... 

Einige 4-substituierte 1-Phenyl-phthalazine werden in 1 n Salzsaure (mit 30—40% Athanol) unter Abspaltung der 4-standigen Substituenten und Ringverengung zu 1-Phenyl-2,3-dihydro-isoindol (70-95% d.Th.) reduziert1 ... 

V-[[l-[4-chloro-2-(2-chlorobenzoyl)phenyl]-3-[(dimethyl-amino)carbonyl]-l/f-l,2,4-triazol-5-yl]methyl]-l,3-dihy-dro-l,3-dioxo-2H-isoindole-2-acetamide (C29H22CI2NSO5 65699-00-5) see Rilmazafone... 

Reduced isoindoles are formed when acetylenes are cooligomerized with N-phenyl- or N-methylmaleimide but the synthetic value of these processes is limited by competing secondary reactions of product cycloaddition (Scheme 51) and oxidation.87... 

Additional examples of these novel SET-promoted photorearrangement reactions were uncovered in our investigations with the 2-azadienes 78 and 82. These substances yield the corresponding A-vinylaziridines 93 and 94, respectively, upon DCA-sensitized irradiation (Structures 93-99). The study was extended to azadiene 73. The DCA-sensitized irradiation of 73 yields the aziridine 95 and the dihydroisoindole 96 [65]. However, under these conditions, 2-azadiene 97 affords, in addition to the expected aziridine 98, the dihydroisoquinoline 99. The formation of the isoindole 96 can be explain by a pathway in which a radical-cation centered on the C—double bond attacks the phenyl ring at C-3, as shown in Scheme 15. The formation of the dihydroisoquinoline 99 can be justified by... 

On heating, 4-(isopropoxy)-2-phenyl-2-(trifluoromethyl)-5(2/i/)-oxazolone 65 underwent decarboxylation to the alkoxy-substituted nitrile ylide 66 that was trapped in a 1,3-dipolar cycloaddition by trifluoroacetophenone to generate 68." Other dipolarophiles reacted similarly. In the absence of a dipolarophile, cyclization of 66 yielded the isoindole 67 (Scheme 7.16 Table 7.11, Fig. 7.12). 

The hydrogenated compound, eAo-hexahydro-4.7-methano-2-phenyl-l/7-isoindole-l,3(2//)-dione, has also been used. Thus, treatment with 2.5 equiv of LDA in THF at — 80 X for 30 min, followed by addition of CH31 (— 80 - +25 X), resulted in a 55% yield of e (fo-hexahydro-4,7-methano-3a,7a-dimethyl-2-phenyl-lF7-isoindole-l,3(2/7)-dione mp 115 — 117 X. 

On pyrolysis, 1-arylimidazoles rearrange to 2-arylimidazoles. In other systems pyrolysis causes more deep-seated changes. 1-Arylbenzotriazoles on pyrolysis or photolysis give carbazoles via intermediate nitrenes (see Section 3.4.1.2.1). 1-Phenyl-1,2,4-triazole (714) is pyrolyzed to isoindole... 

Synthesis of benzo[c]furans and isoindoles (181) is also possible by the addition of benzyne to the respective monocycles (178), followed by reduction (179 — 180) and pyrolysis. In an alternative procedure, (179) is reacted with 3,6-bis(2-pyridyl)-l,2,4,5-tetrazine, which affords (181) under far less vigorous conditions via a retro Diels-Alder reaction of the intermediate (182). 4-Phenyl-1,2,4-triazoles pyrolyze to form isoindoles (Section 3.4.3.12.2). 

Predictably, isoindole is a stronger base than pyrrole, the conjugate acid of which has a pKa of -3.8 on the H0 scale (-4.4 on the Hr scale). From the few measurements that are available, isoindoles having phenyl groups at the 1,3-positions are protonated at the... 

The acetylation of carbazole by acetic anhydride in the presence of boron trifluoride produces the 9-acetyl derivative. Further acetylation requires more vigorous conditions, using aluminum trichloride as a catalyst, and yields 2,9-diacetylcarbazole, which, upon base-catalyzed hydrolysis, produces 2-acetylcarbazole (80T3017). Acetylation of 1-phenyl-isoindole under mild conditions in the presence of pyridine yields l-acetyl-3-phenylisoin-dole, whereas the presence of an ester group at the 1-position deactivates the ring sufficiently to prevent acylation (81AHC(29)34l). 

When acrylonitrile or ethyl acrylate was used as the dipolarophile, the azomethine adducts (134) and (135) were formed no thiocarbonyl ylide addition products were isolable in refluxing toluene or xylene, although the isoindoles (136a) and (136b) derived from them were isolated. In contrast to the reactions with fumaronitrile or AT-phenylmaleimide, the azomethine adducts (134) and (135) were still present at higher reaction temperatures — almost 50% in toluene and 4-5% in xylene. Under the same reaction conditions other electron-deficient dipolarophiles like dimethyl fumarate, norbornene, dimethyl maleate, phenyl isocyanate, phenyl isothiocyanate, benzoyl isothiocyanate, p-tosyl isocyanate and diphenylcyclopropenone failed to undergo cycloaddition to thienopyrrole (13), presumably due to steric interactions (77HC(30)317). 

The previous example took inspiration from earlier work of Lin et al.18 In their seminal work, Lin and coworkers functionalized the inner pores of MCM-41 with o-phthalic hemithioacetal moieties that are able to react with amines to produce a highly fluorescent isoindole derivative. In order to enhance selectivity in the sense we have discussed above, the solids were also hydrophobized with different groups such as propyl, phenyl, and pentafluorophenyl in a second step. Interestingly, some of these solids displayed a remarkably selective and differentiable response to dopamine versus the less lipophilic glucosamine. The authors also demonstrated that this selectivity was not observed when amorphous (nonporous) silica functionalized with the same organic groups was used, stressing the importance of the 3D... 

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