Acridine and derivatives

ACRIDINE AND DERIVATIVES Acridine or Dlbenzopyridlne (2.3 5.6-Di-benao-pyridin, in Ger),... 

Acridine and derivs 1 A94-A95 acridine dichromate 1 A95 acridine nitrate 1 A95 acridine perchlorate 1 A95 acridine picrate 1 A95 acridine-1,3,5-trinitrobenzene salt 1 A95 dinitroacridine 1 A94 mononitroacridine 1 A94... 

Except for the tetrahydrobiaryls derived from acridine and from quinoxaline, the postulated intermediate tetrahydrobipyridines have not been isolated but such compounds may be too unstable under the conditions of the reaction to permit their isolation. Evidence is, therefore, still lacking for the last two steps of dehydrogenation and desorption from the catalyst. Dehydrogenation could conceivably occur while the tetrahydro derivative is still adsorbed on the catalyst,... 

Acridine and its derivatives are also fused nitrogen heterocycles similar to acridones, which display a high fluorescence quantum yield and possess the ability to intercalate tightly, though reversively, to the DNA helical structure [73], with large binding constants [74]. As a result, acridine dyes are recognized in the field of the development of probes for nucleic acid structure and conformational determination [75-77]. 

Kaiser, J.-P. Feng, Y., and Bollag, J.-M., Microbial Metabolism of Pyridine, Quinoline, Acridine, and Their Derivatives Under Aerobic and Anaerobic Conditions. Microbiological Reviews, 1996. 60(3) pp. 483-498. 

As a general trend, six-membered mononuclear N-heteroaromatics such as pyridine and derivatives are much less prone to undergo hydrogenation than bi-and trinuclear N-ring compounds (e.g., quinolines, benzoquinolines, acridines) due to their higher resonance stabilization energy. 

Although chlorination, bromination and iodination of thiophenes by polyhalide salts require forcing conditions with the addition of zinc chloride [52], halogenation of acridine and acridone has been recorded to yield both 3-halo and 3,7-dihalo derivatives under relatively mild reaction conditions [53], However, whereas chloro-, bromo- and iodo-compounds are readily obtained from acridone, acridine only forms the bromo derivatives, as it produces stable complexes with the dichloroiodate and tetrachloroiodate salts [53]. 

Azonia substitution at a naphthalene bridgehead position gives the quinolizinium ion (16). Oxonia substitution, elsewhere, forms the 1- and 2-benzopyrylium ions (17) and (18). The two most well-known monoaza systems with three aromatic fused rings are acridine (19), derived structurally from anthracene, and phenanthridine (20), an azaphenanthrene. The better-known diaza systems include phenazine (21) and 1,10-phenanthroline (22), while systems with three linearly fused pyridine rings are called anthyridines, e.g. the 1,9,10-isomer (23). 

Protonated pyridines and derivatives readily undergo acylation at C-2 or C-4 (Table 28) (76MI20503). Acyl radicals are usually generated either by hydrogen abstraction from aldehydes (Scheme 210), or by oxidative decarboxylation of a-keto acids (Scheme 211). In the former case (Scheme 210) with acridine as the substrate, reduction can take place to give a dihydroacridine. 

Friedel-Crafts acylation fails with quinoline, isoquinoline, acridine and many derivatives. However, when sufficient activation is present substitution can result. For example, 8-methoxyquinoline (28) in the presence of aluminum chloride and acetyl or benzoyl chloride gives the 5-acetyl and 5-benzoyl derivatives in 25% and 35% yields respectively. 

Table III summarizes experimental and theoretical data on the first three absorption bands (Lb, La, Bb) in the spectra of pyridine, quinoline, isoquinoline, acridine, and their benzo and dibenzo derivatives.

The chemistry of thienoquinolines has been explored to a limited degree. Two types (378,379) will be described in this subsection. The pharmacological interest in thieno[2,3-Z>]quinoline (378) and derivatives thereof stems from their isosteric and isoelectronic resemblance to acridine furthermore, (378) constitutes the sulfur analog of furoquinoline (Section 3.17.2.1.5), which is the parent system of a number of alkaloids. Thieno[3,4-6]quinoline (379) is an o-quinonoidal heterocycle which is of interest both for theoretical reasons compared with its isoconjugate analogues and as a synthon in Diels-Alder reactions for the preparation of other condensed heterocycles. 

McEachern, D.M., Sandoval, O., Iniguez, J.C. (1975) The vapor pressures, derived enthalpies of sublimation, enthalpies of fusion, and resonance energies of acridine and phenazine. J. Chem. Thermodyn. 1, 299-306. 

Korth C, May BCH, Cohen FE, Prusiner SB. Acridine and phenothiazine derivatives as pharmacotherapeutics for prion disease. Proc. Natl. Acad. Sci. USA,... 

Levin W, Wood AW, Chang RL, Kumar S, Yagi H, Jerina DM, Lehr RE, Conney AH (1983) Tumor-initiating activity of benz[c] acridines and twelve of its derivatives on mouse skin. Cancer Res 43 4625-4628... 

This chapter focuses on the progress and challenges in the field of photocatalysis as applied towards the water splitting reaction (Eq. 1.). More specifically, homogeneous molecule based systems that mimic the natural photosynthetic system are examined for their potential to drive reaction 1. A number of molecules, including porphyrins, metalloporphyrins and phthalocyanines,17 transition metal complexes of Ru, Os, Re, Rh, Pt, Cu,811 and acridine and flavin derivatives,1214 have been examined as the chormophores and sensitizers for light driven processes. 

Photoaddition of nucleophiles to heterocycles is often observed.1 Irradiation of acridine and its quaternary salt in ethanol produced 9,9 -bisacridan (151) as the major product besides a little acridan and 9a-hydroxyethylacridan.207 The reaction mechanism is most likely a hydrogen abstraction from the alcohol by the excited molecule, followed by competitive radical combination to yield 151. Irradiation of an aqueous solution of alloxan monohydrate and its derivatives produces an alloxantin-type dimer (152 R = H, Me, Et) by combination (at the 5-position) of a radical intermediate.208... 

Acridine Syntheses and Reactions. Part VI. A new dehalogenation of 9-chloro-acridine and its derivatives. Further acridine ionization constants and ultraviolet spectra. 

Klingsberg, E. and Newkome, G.R., Eds., Pyridine and Its Derivatives, Interscience, New York, 1960 Schoefield, K., Heteroaromatic Nitrogen Compounds Pyrroles and Pyridines, Butterworths, London, 1967 Hurst, D.T., An Introduction to the Chemistry and Biochemistry and Pyrimidines, Purines, and Ptreridines, J. Wiley, Chichester, UK, 1980 Plunkett, A.O., Pyrrole, pyrrolidine, pyridine, piperidine, and azepine alkaloids, Nat. Prod. Rep. 11, 581-590, 1994 Kaiser, J.P., Feng, Y., and Bollag, J.M., Microbial metabolism of pyridine, quinoline, acridine, and their derivatives under aerobic and anaerobic conditions, Microbiol. Rev. 60, 483-498, 1996. 

Reductive dimerization of benzene [246], cyano biphenyl ether [247], pyridine [248], and acridine [249] derivatives has also been investigated. Radical anions of diesters of pyridine and benzene undergo rapid reversible dimerization (A dim = 10 -10 M" s" ) [250]. 

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