Bis-anthraquinones

Anthrimide [l,l -imino-bis-anthraquinone] [82-22-4] M 429.4, m >250 (dec). Crystd from chlorobenzene (red needles) or nitrobenzene (red rhombs)... 

Mori S, Kawai K, Nozawa Y, Ogihara Y (1998) The Redox Reaction and Biotransformatirai of Rubroskyrin, a Modified bis-Anthraquinone from Penicillium islandicum Sopp. Nat Toxins 6 85... 

The furanocoumarin derivative, 5-methoxypsoralen, and other related compounds, are responsible for the phototoxicity of various essential oils on skin (9, 65, 169). Other studies with lapachol concern its toxicity to viruses (98) and parasites (102). The sensitizing capacity of naphthoquinones was studied on guinea pigs (166). The problem of photosensitization was present in livestock (93). The effects were caused by 5-methoxypsoralen, and also the bis-anthraquinone hypericin. The flavanoids are thought to be responsible for a contact eczema from Robinia sp. (190). 

Preparative-layer chromatography has been used in some cases, especially when small quantities of substance are involved. Culberson and Kristinsson (1969) separated some depsides on silica gel plates with Pastuska s mixture. Piattelli and Guidici de Nicola (1968) isolated anthraquinones, Santesson (1970a) isolated bis-anthraquinones and Santesson (1969b) isolated xan-thones, in all cases on silica-gel plates. Bloomer et al. (1970a,b) reported on preparative-layer chromatography of some aliphatic lichen acids and Aberhart et al. (1970) isolated portentol and its acetate by PLC. 

Bis (dinitrophenoxyl) 4 8-dinitro anthraquinone 10.5 Combustion propagates fully and... 

C-NMR. The structures of the leuco derivatives of l,4-bis(butylamino)-anthraquinone (14) and l-butylamino-4-hydroxyanthraquinone (15) have been shown to be l,4-bis(butylamino)-2,3-dihydroanthracene-9,10-dione (16a) and l-butylamino-10-hydroxy-2,3-dihydroanthracene-4,9-dione (17a), respectively. On the other hand, leuco-1,4-dimethoxyanthraquinone has been assigned the structure, 1,4-dimethoxy-9,10-dihydroxyanthracene (18). 

It is well known that quinizarin (22) is alkylaminated in air to give a mixture of l-alkylamino-4-hydroxyanthraquinone (23), l,4-bis(alkylamino)-anthraquinone (24), and 2-alkylaminoquinizarin (25) (Scheme 7). The reaction conditions affect the ratio of these products. In a nitrogen atmosphere, or in the presence of sodium dithionite as reducing agent, the main amination product is 24. The solvent effects of the reaction of leuco... 

Derivatives of diaminoanthrarufin (3.77 X = Y = H) and its 1,8-dihydroxy-4,5-diamino isomer (diaminochrysazin) have been among the most widely used anthraquinone dyes for ester fibres. For example, methylation of diaminoanthrarufin gives Cl Disperse Blue 26, a mixture of several components. Study of the pure N-alkylated derivatives from the base confirmed that monosubstitution (3.77 X = H, Y = alkyl) gives mid-blue dyes with excellent dyeing properties and acceptable fastness on polyester, but the bis-alkyl dyes (3.77 X = Y = alkyl) are greener and inferior in application properties. Mixtures of the unsubstituted base with alkylated components, as obtained industrially, were especially advantageous for build-up to heavy depths, however [93]. 

Other anthraquinone/azo pigments are obtained by coupling 1-aminoanthraquinone derivatives onto bis-quinazolinone methanes with the following chemical structure 82 ... 

Dimethylamino-anthroquinone. See Bis(me-thylamino)-anthraquinone in Vol 2 of Encycl, p B148-R... 

Di(picrylamino)-anthraquinone. See Bis-(trinitroanilino)-anthraquiaone under Bis-(anilino)-anthraquinone in Vol 2, p B131-L... 

ANTHRAQUINONES 1,3-Bis(lrime tliyE silyIoxy)-l, 3-butadicne. scc-Butyllithi-um. Lithium o-Uthiobenzoate. 3-Phenyl-sulfony 1-1 (3H)-isobenzofuranone. 

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