2.4- Dihydroxybenzophenone benzophenone

Benzophenone, 4,4 -dihydroxy-. See 4,4 -Dihydroxybenzophenone Benzophenone, 2-hydroxy-4-(octyloxy)-. See Benzophenone-12 2-Benzophenone, methyl-. See 2-M ethyl benzophenone p-Benzophenone, methyl-. See 4-M ethyl benzophenone Benzophenone, 4-phenyl-. See p-Phenylbenzophenone 4-Benzoyl biphenyl Benzophenone tetracarboxylate dianhydride 3,3, 4,4 -Benzophenonetetracarboxylate dianhydride. See 3,3, 4,4 -Benzophenone tetracarboxylic dianhydride... 

Nitrobenzotrichloride is also obtained in high yield with no significant hydrolysis when nitration with a mixture of nitric and sulfuric acids is carried out below 30°C (31). 2,4-Dihydroxybenzophenone [131 -56-6] is formed in 90% yield by the uncatalyzed reaction of benzotrichloride with resorcinol in hydroxyHc solvents (32) or in benzene containing methanol or ethanol (33). Benzophenone derivatives are formed from a variety of aromatic compounds by reaction with benzotrichloride in aqueous or alcohoHc hydrofluoric acid (34). 

Very early in the study of photosensitization it was discovered that salicylaldehyde, 2,4-dihydroxybenzophenone, and 2-hydroxy-4-methoxy-benzophenone do not sensitize piperylene isomerization, indicating that enolization is much faster than quenching by the diene.37 Later it was shown that 2-hydroxybenzophenone would sensitize the dimerization of isoprene in concentrated solution, but that the reaction was much less efficient than when benzophenone was used as a sensitizer (Table I).36... 

A biogenetic flavour is apparent in the formation of dihydroxybenzophenones by the reaction of o-hydroxybenzoate esters with the trianion of heptane-2,4,6-trione (81JOC2260). Acylation of the trianion occurs at 0-25 °C to give a tetraketone which cyclizes under mildly basic conditions to the corresponding benzophenone. A second ring closure takes place when the benzophenone is treated with sodium methoxide, leading to the xanthone (Scheme 188). 

The best known and most commonly used ingredients of UV filters are compounds from the group of benzophenones (BPs), mainly 2,4-dihydroxybenzophenone (BP-1) and 2-hydroxy,4-methoxy benzophenone (BP-3). Their structures are depicted in Figs. 7.6 and 7.7. 

Although only a few imines are stable in aqueous solution, reduction in cold 50% sulfuric acid at a lead cathode may give the amine [15,16]. In this connection it can be mentioned that 2,4-dihydroxybenzophenone oxime on reduction on the first wave in acid solution gives an imine stable enough to be isolated [17]. Schiff bases of some other benzophenone derivatives are stable in acid solution their reduction is a straightforward saturation of the azomethine group [18,19]. 

The other mechanisms for the intramolecular reaction of benzophenone involve quinone addition [26], dehydration between hydroxyl groups on acetate- and shikimate-derived rings (2,2 -dihydroxybenzophenone) [27], or spirodienone formation and subsequent rearrangement to form the xanthone [22,28]. 

Allyl groups have also been introduced in the 3 position of 2,k-dihydroxybenzophenone. Nucleophilic displacement reaction of the chloride in It—chloromethylstyrene by phenolates of 2,1+-dihydroxy-benzophenone (9) or 2(2-hydroxy-5-methylphenyl)l4- -hydroxybenzotria-zole also provided a method of producing styrene-type polymerizable ultraviolet stabilizers (9,10). 

Beilstein Handbook Reference) 4,4 -Dimethoxy-2,2 -dihydroxybenzophenone Benzophen-one, 2,2 -dihydroxy-4,4 -dimethoxy- Benzophenone-6 Bis(2-hydroxy-4-... 

Xanthochymol (138), to our knowledge, is the only benzophenone analyzed, in detail, for its electron impact MS fragmentation behavior [110]. Reported MS losses for benzophenones include an m/z 105 (CsHs-CO4) for a unsubstituted phenyl ketone A-ring [44,65], m/z 137 (G,H O3-CO4) for a 3,4-dihydroxybenzophenone moiety, and m/z 68 (CsHg) for a prenyl-type group. 

CAS 131-56-6 EINECS/EEINCS 205-029-4 Synonyms Benzoresorcinol 4-Benzoyl resorcinol BP1 DHBP 2,4-Dihydroxybenzophenone (2,4-Dihydroxyphenyl) phenylmethanone Methanone, (2,4-dihydroxphenyl) phenyl-ClassiTicatbn Organic benzophenone deriv. 

CAS 131-56-6 EINECS/ELINCS 205-029-4 Synonyms Benzoresorcinol 4-Benzoyl resorcinol BP1 DHBP 2,4-Dihydroxybenzophenone (2,4-Dihydroxyphenyl) phenylmethanone Methanone, (2,4-dihydroxphenyl) phenyl-Classification Organic benzophenone deriv. Empirical C13H10O3 Formula C6HsCOC6H3(OH)2 Properties Off-wh. to It. yel. cryst. solid sol. in ethanol, methanol, MEK, ethyl acetate insol. in water m.w. 214.23 m.p. 142 C b.p. 194 C (1 mm)... 

Bis (p-hydroxy) benzophenone. See 4,4 -Dihydroxybenzophenone Bis (2-hydroxy-3-t-butyl-5-ethylphenyl) methane. See 2,2 -Methylenebis (4-ethyl-6-t-butylphenol) Bis (4-hydroxy-5-t-butyl-2-methylphenyl) sulfide. See 4,4 -Thiobis-6-(t-butyl-m-cresol) Bis-2-hydroxy-5-chlorophenyl) methane. See Dichlorophene... 

Methanone, bis (4-(diethylamino) phenyl)-. See 4,4 -Bis (diethylamino) benzophenone Methanone, bis (4-hydroxyphenyl)-. See 4,4 -Dihydroxybenzophenone Methanone, (5-chloro-2-hydroxyphenyl) phenyl-. See Benzophenone-7... 

Camphorquinone 4,4 -Dihydroxybenzophenone 4-(Dimethylamino) benzophenone 4,4 -Dimethylbenzil 2,5-Dimethyl benzophenone 3,4-... 

C13H10O3 Benzophenone-1 4,4 -Dihydroxybenzophenone Diphenyl carbonate Phenylparaben Phenyl salicylate Resorcinol benzoate C13H10O4... 

Chamoumi and Brunei investigated the liquid phase rearrangement of 1,2-epoxyalkenes over various zeolites [96]. H-Offretite gave the best selectivity for the formation of octanal in the reaction with 1,2-epoxyoctane. The esterification of resorcinol with benzoic acid derivatives is followed by a Fries rearrangement to give benzophenones [97]. The reaction is catalysed by Amberlyst-15 ion-exchange resin or Nafion-17 acidic exchange resin. 2,4-Dihydroxybenzophenone has been synthesised in 88% yield by this method. 

Tetrahydroxybenzophenone, 3,4,5,2 ,3 ,4 -hexahydroxybenzophenone, and 4,4 -dihydroxy-benzophenone displayed an inhibitory effect on xanthine oxidase with an order of activity of IC50 = 47.59, 69.40 and 82.94 pM, respectively (Sheu et al. 1999). The apparent inhibition constants (Ki) of 3,4,5,2 ,3 ,4 -hexahydroxybenzophenone and 4,4 -dihydroxybenzophenone were 15.61 and 64.86 pM, respectively, and both of the induced mixed-type (non-competitive-uncompetitive) inhibitions of the substrate xanthine. 

Preparation lirom 2,4-dihydroxybenzophenone as starling material via the 2-hydroxy-4-meth-oxymethoxy-benzophenone and 2-benzoyloxy-4-methoxymethoxy-benzophenone [429],... 

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