12‐Organyldibenz[b,g]azocin‐5,7‐dione

Abstract

Die Titelverbindungen 10, 23 entstehen in schlechten Ausbeuten bei der Umsetzung von 2,2'-Organyliminobisbenzoesaureestern 8 rnit Methyllithium, hingegen in sehr guten Ausbeuten bei der intramolekularen Esterkondensation von mit o-Acetyl-und 0'-Methoxycarbonyl-Gruppen versehenen Triarylaminen 12 rnit Natriumhydrid. Mit iiberschiissigem Natrium-oder Lithiumhydrid reagieren die ausschliefilich in der p-Diketoform vorliegenden Heterocyclen zu den entsprechenden Enolaten, die sich rnit Iodmethan zu Gemischen von C-und 0-methylierten Derivaten umsetzen lassen. Nucleophile wie Hydroxylamin, Arylhydrazine, Methyllithium, aber auch Lithiumaluminiumhydrid kondensieren bzw. addieren an die Carbonylgruppen, wiihrend KOH in Methanol Ester-bzw. Saurespaltung unter Ringsprengung bewirkt. Elektrophile reagieren bevorzugt an den N-Arylgruppen, unter verscharften Bedingungen aber auch an den Geriistaromaten; starke Sauren jedoch fiihren unter formaler Ketenextrusion und Ringverengung zu Acridonen 31 und 33. 12-Organyldibenz[bg]azocine-S,7dionesThe title compounds 10, 23 are formed in low yields on treatment of 2,2'-organyliminobisbenzoic acid esters 8 with methyllithium, but in high yields in the intramolecular ester condensation with sodium hydride of triarylamines 12, containing o-acetyl-and 0'-methoxycarbonyl groups. The new heterocycles exist exclusively in the p-diketo form and react with excess sodium-or lithium hydride to give the corresponding enolates. These, on treatment with iodomethane, form mixtures of C-and 0-methylated derivatives. Nucleophiles such as hydroxylamine, arylhydrazines, methyllithium and also lithium aluminium hydride condense or add to the carbonyl groups, while KOH in methanol leads to ester or acid cleavage under ring opening. Electrophiles react predominantly at the N-aryl groups but under more severe conditions also at the frame arenes. Strong acids, however, under formal ketene extrusion and ring contraction lead to acridones 31 and 33.Im Produktgemisch der Umsetzungen von 2,2',2-Nitrilotrisbenzoesaure-trimethylester (1) rnit Methyllithium konnten seineneit, je nach Bedingungen, aul3er dem voll durchreagierten dreifachen Carbinol2d auch alle moghchen Zwischen-

Palladium-Catalyzed Amination of Aryl Nonaflates

“…N -(2-Methoxycarbonylphenyl)-aniline (Table , entry 4). With the general procedure, a solution of methyl 2-[(nonafluorobutanesulfonyl)oxy] benzoate (200 mg, 0.480 mmol), Pd 2 dba 3 (4.2 mg, 0.0046 mmol), ligand 5 (5.3 mg, 0.0092 mmol), aniline (0.051 mL, 0.55 mmol), and K 3 PO 4 (137 mg, 0.640 mmol) in toluene (1.5 mL) was stirred at 105 °C for 14 h. The crude material was purified by column chromatography on silica gel (eluting with ethyl acetate/hexane, 1:10) to give the title compound as a pale yellow solid (95 mg, 91%), mp 52−54 °C (lit . mp 54−56 °C).…”

The Complementary Competitors: Palladium and Copper in C–N Cross-Coupling Reactions

“…The synthesis of triarylamines by the classical Ullmann method by heating iodoarenes with diarylamines in the presence of K 2 CO 3 and copper powder at high temperature in high-boiling solvents has long been the only practical access to triarylamines. A few modifications were made to perform the reactions under milder conditions, though this could be done only for selected specific substrates: e.g., ortho-substituted aryl iodides bearing electron-withdrawing directing substituents . Such a modified procedure has been successfully used to prepare various diaryl- and triarylamine materials in the post-Ullmann epoch .…”

“…A few modifications were made to perform the reactions under milder conditions, though this could be done only for selected specific substrates: e.g., orthosubstituted aryl iodides bearing electron-withdrawing directing substituents. 175 Such a modified procedure has been successfully used to prepare various diaryl-and triarylamine materials in the post-Ullmann epoch. 176 Recently it was shown that the temperature of the "ligand-free" reaction can be lowered to 145 °C through the use of the unusual solvent Si(OEt) 4 and the stronger base Cs 2 CO 3 .…”

Aza-aromatic polycycles based on triphenylene and acridine or acridone: synthesis and properties

“…Similarly, the conversion of the aldehyde into the ethyl ester 5, by using iodine and potassium hydroxide in ethanol, 34 failed (very low conversion). Thus, we selected ethyl anthranilate to perform its N-arylation 30,36 with 2-iodotriphenylene towards the diarylamine 5, isolated in 88% yield. After hydrolysis of the ester function, 37 the carboxylic acid 6 was treated by phosphorus(V) oxychloride under reflux 37 for 3 days.…”