Synthesis of Carbazole, Acridine, Phenazine, 4H‐Benzo[def]carbazole and Their Derivatives by Thermal Cyclization Reaction of Aromatic Amines.

Abstract

Ring closure reactions Ring closure reactions O 0130Synthesis of Carbazole, Acridine, Phenazine, 4H-Benzo[def]carbazole and Their Derivatives by Thermal Cyclization Reaction of Aromatic Amines. -An intramolecular cyclization reaction of aromatic amines yields nitrogen-containing fiveand six-membered heterocycles by passing vapors of the amines over calcium oxide at 450-650°C under nitrogen carrier gas. The reactions are carried out with 2-amino--2'-substituted biphenyls as well as with amines having a carbon-, nitrogen-, or oxygen--containing linker group between two benzene rings. Additionally, the intramolecular cyclization behavior of aminophenanthrene (XIV) is investigated. At present, the reaction mechanism is not yet clear. -(HORAGUCHI*, T.; OYANAGI, T.; CREENCIA, E. C.; TANEMURA, K.; SUZUKI, T.; J. Heterocycl. Chem. 41 (2004) 1, 1-6; Dep. Chem., Fac. Sci., Niigata Univ., Ikarashi, Niigata 950-21, Japan; Eng.) -H. Hoennerscheid 26-036

Occurrence, Biogenesis, and Synthesis of Biologically Active Carbazole Alkaloids

“…In 2004, Horaguchi et al prepared carbazole ( 1 ) by passing the vapor of 2-aminobiphenyl ( 43.1 ) over calcium oxide at 560 °C using nitrogen as carrier gas (Scheme ) . Mechanistically this reaction is believed to proceed via deprotonation by calcium oxide to generate an amide ion that subsequently cyclizes by attack at the phenyl substituent.…”

Tuning CO2Electroreduction of Cu Atoms on Triphenylene-Cored Graphdiyne

“…These modifications are experimentally feasible. 30,31 Structure relaxations and single-point energy calculations are performed using density functional theory as implemented in the Vienna ab initio simulation package (VASP); 32 the projector-augmented-wave (PAW) 33 pseudopotential is utilized to treat the core electrons, while the revised Perdew− Burke−Ernzerhof (RPBE) 34 exchange−correlation functional of the generalized gradient approximation (GGA) is used for describing the electron interactions as the RPBE has been proved to have better accuracy than Perdew−Burke− Ernzerhof (PBE) 35 exchange−correlation functional. A planewave cutoff energy of 520 eV is adopted for all the calculations.…”

[4 + 2] Annulation of 3-Nitroindoles with Alkylidene Malononitriles: Entry to Substituted Carbazol-4-amine Derivatives

“…Horaguchi and co-workers have developed one example concerning thermal cyclization of 2,2′-diaminobiphenyl over calcium oxide under harsh conditions to deliver the major carbazol-4-amine with concomitant formation of a large amount of byproduct carbazole (Scheme 1a). 6 Moreover, the preparation of substituted carbazol-4-amine using this method is unknown. The reduction of 4-nitrocarbazole derivatives prepared by late-stage nitration of substituted carbazoles under catalytic hydrogenation has also been developed in the course of synthesis of antiostatins (Scheme 1b).…”