Salts acridinium

It has been recrystd from H2O (fine needles) and is freely soluble in boiling H2O. Crysts also from H2O by addition of acetone. Purified by chromatography on Dowex 1 (in formate form), eluting with 0.25M formic acid. It was then adsorbed onto charcoal (which had been boiled for 15min with M HCI, washed free of chloride and dried at 100°), and recovered by stirring three times with isoamyl alcohol/H20 (1 9 v/v). The aqueous layer from the combined extracts was evaporated to dryness under reduced pressure, and the product was crystallised twice from hot H2O. [Morrison and Doherty Biochem J19 433 7967]. It has A-max 259nm (e 15,400) in H2O at pH 7.0. [Alberty et al. J Biol Chem 193 425 7957 Martell and Schwarzenbach Heh Chim Acta 39 653 7956]. The acridinium salt has m 208° [Baddiley and Todd J Chem Soc 648 1947 Pettit Synthetic Nucleotides, van Nostrand-Reinhold, NY, Vol 1 252 1972 NMR Sarma et al. J Am Chem Soc 96 7337 1974 Norton et al. J Am Chem Soc 98 1007 1976 IR of diNa salt Miles Biochem Biophys Acta 27 324 1958],... 

Heald RA et al. (2002) Antitumor polycyclic acridines. 8.(1) Synthesis and telomerase-inhibitory activity of methylated pentacyclic acridinium salts. J Med Chem 45(3) 590-597... 

Hutchinson 1 et al. (2004) Synthesis and properties of bioactive 2- and 3-amino-8-methyl-8H-quino[4,3,2-kl]acridine and 8,13-dimethyl-8H-quino[4,3,2-kl]acridinium salts. Org Biomol Chem 2(2) 220-228... 

Me Capra in particular proposed n> that the chemiluminescence reactions of a large number of organic compounds had this concerted dioxetane decomposition step as key reaction in the production of electronically excited products, namely acridinium salts 25,26,27) indolylperoxides 28>, activated oxalic esters 29>, diphenyl carbene 30>, tetrakis-dimethylamino-ethylene 31 32>, lucigenin 33>, and substituted imidazoles 23>. 

The oxidative behaviour of the acridinium carbocations 61 was also explored by the group of Lacour in the photoinduced electron transfer reaction [160]. In the amount of 2 mol%, the achiral hindered acridinium salt 61 catalyzed the aerobic photooxidation of the primary benzylic amine to benzylimine in the yield of 74% (Scheme 63). 

In the presence of hydrogen peroxide and base, acridinium salts lead to chemiluminescence emission. Acridans, in their reduced forms, are able to react directly with oxygen in aprotic solvents with 4>cl up to 10% . Scheme 31 shows the proposed mechanism for chemiluminescence of 9-cyano-lO-methylacridan and 9-cyano-lO-methylacridinium salt in the presence of oxidant and base, which postulates the cyclic peroxidic intermediate 44. 

Chemically Initiated Electron Exchange Luminescence (CIEEL) acridinium salts, 1256 alkaline phosphatase, 1193-8 1,2-dioxetanes, 1182-200 firefly bioluminescence, 1191-3 intermolecular, 1213-15, 1231-6 intramolecular, 1214-15, 1236-8 luminol, 1247-8... 

An example of disproportionation to (109) and (110) is provided by the behaviour of the berberinium ion in alkaline solution (Scheme 62). The pseudobase of the 5-methyl-phenanthridinium cation is present even in neutral solution (equation 85). Attack at position 9 in acridinium salts is also very easy, and they rearrange to pseudobases in a few minutes in alkaline solution. These pseudobases, unlike the others described, do not undergo ring opening. They readily disproportionate or are oxidized to acridin-9-ones by air when the starting salt is unsubstituted at C-9 (B-78MI20502). Pyridine 1-oxides and their analogues... 

Like acridinium salts, isoquinolinium salts disproportionate very easily in alkaline solution. In an extensive study. Bunting and Kabir (78JOC3662) investigated the crossed disproportionation of 166 with 167 to give 168 and 169 (Scheme 27). 

I95I-, Martell and Schwarzenbach HCA 39 653 1956. The acridinium salt has m 208° [Baddiley and Todd... 

A retro hetero Diels-Alder reaction to release an anthracene derivative 9-9 and nitroxyl (HNO) from the corresponding cycloadduct 9-8 by a catalytic antibody has been described by Reymond and Lerner [565]. As a haptene the acridinium salt 9-10 was used (Fig. 9-3). The antibody obtained is of great biological interest as a prodrug release system since the liberated nitroxyl is easily oxidized by the ubiquitous enzyme superoxide dismutase to give nitric oxide (NO) which acts as a chemical messenger for several important bioregulatory processes. 

In addition to their implication as reactive intermediates in bioluminescence, dioxetanones have been proposed as key intermediates in several chemiluminescent systems. Most notable are the chemiluminescent oxidation reaction of acridan esters [19] and the chemiluminescent reaction of the related acridinium salts [20] (Rauhut et al., 1965a McCapra et al., 1977). Both reactions are quite efficient at generating singlet excited states (pCE = 10% and 2% respectively) and, owing to the elegant work of McCapra and others, are among the best understood complex chemiluminescent reaction mechanisms. 

The heteroarylation of thiazolidinones has been accomplished with IV-acyl-pyridinium, -quinolinium, -isoquinolinium, and -acridinium salts [Eq. (32)].148 Alkaline hydrolysis of 103 serves as a convenient source of heterocyclic thioglycolic acids. 

---