4,4 -Dihydroxy benzophenone

Beim 2,4-Dihydroxy-benzophenon-oxim kann durch potentialkontrollierte Reduktion (-0,7 V) an Quecksilber in 1 n Salzsaure mit etwas Athanol die Imin-Zwischenstufe als Hydrochlorid abgefangen werden7 (s. S. 699). 

Figure 6.1 Reaction of dihydroxy benzophenone (DHBP) with epichlorohydrin to form l2-hydroxy-4-(2,3-epoxypropoxy)benzophenone] (HEBP).

In the isoelectionic ruthenium series, nucleophilic substitution by the disodium salt of 4,4 -dihydroxy-benzophenone on the complex (32) of p-dichlorobenzene with a [RuCp]+ unit produced the aromatic polyether complex represented by (33). Displacement by DMSO at 160 C led to the free polymer and the recoverable complex [CpRu(DMSO)3]+, which can be recycled directly by complexation with p-dichlorobenzene (equation 26). While ruthenium is not attractive to use in stoichiometric processes, this example appears to allow easy recycling.80... 

Determination of 1,2-dihydroxybenzene, 1,3-dihydroxybenzene, 1,4-dihydroxybenzene, 4,4 -dihydroxy-benzophenone and 4,4 dihydroxybiphenyl in food simulants Determination of dimethylaminoethanol in food simulants Determination of ethylenediamine and hexamethylene-diamine in food simulants... 

Estimated from pKg values of similar compounds 4-hydroxy benzo-phenone -5.03 4-methoxy benzophenone -4.93 2,4-dihydroxy benzophenone -4.82 (91). 

A number of polymerizable ultraviolet stabilizers have been synthesized and their homo- and copolymerization studied. The initial work consisted of the synthesis of vinyl derivatives of methyl salicylate (three isomers), 2, -dihydroxy-benzophenone, and ethyl a-cyano-p-phenylcinnamate. More recently, vinyl derivatives (two isomers) and one isopro-penyl derivative of 2(2-hydroxyphenyl)2H-benzotriazole have been prepared. A number of benzotriazoles with more than one benzotriazole ring in the molecule, or compounds with both benzo(or aceto)phenone and 2(2-hydroxyphenyl)2H-benzo-triazole groups in one molecule, have also been synthesized. Acryloyl and methacryloyl derivatives of benzotriazole-substituted polyphenols have been prepared and homo- and copolymerized. 

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). 

The following photostabilizers were used 2-hydroxy-benzophenone (I) (Merck, Germany), 2,2 -dihydroxy-benzophenone (II) (Aldrich, Belgium) and 2(2 -hydroxy-5-methylphenyl)benzotriazole (III)... 

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. 

The most effective light stabilizers based on benzophenone are cited in Table 11. Their recommended concentrations for polyolefins are 0.2-1.5% by weight. Light stabilizers based on benzophenone can be divided into two basic tsqjes mono-2-hydroxybenzophenones and 2,2 -dihydroxy-benzophenones. 

Stabilizers UVA 2-hydroxy-4-methoxybenzophenone 2,4-dihydroxy-benzophenone 2-benzotriazol-2-yl-4,6-di-tert-butylphenol 2-(2H-benzotriazole-2-yl)-4,6-di-tert-pentylphenol N-(2-ethoxyphenyl)-N -(4-isododecylphenyl)oxamide HAS decane-dioic acid, bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) ester, reaction products with 1,1-dimethylethylhydroperoxide and octane 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetra-methylpiperidin-4-yl)amino]-6-(2-hydroxyethylamine)-1,3,5-trlazlne bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate 2-dodecyl-N-(2,2,6,6-tetramethyl-4-piperidinyl)succinimide polymer of 2,2,4,4-tetramethyl-7-oxa-3,20-diaza-dispiro [5.1.11,2]-hene-lcosan-21-on and epichlorohydrin Screener Ti02 Phosphite phosphoric acid, (2,4-di-butyl-6-methylphenyl)ethylester ... 

Preparation by reaction of n-octyl p-toluenesulfonate with 2,4-dihydroxy-benzophenone,... 

Preparation by reaction of chlorom-ethyl methyl ether with 2,4 -dihydroxy-benzophenone monosodium salt (4 ) in tolnene at r.t. overnight (64%) [1021]. 

Preparation by condensation of 2,4-dihydroxy-benzophenone with 1,3-butadiene in the presence of orthophosphoric acid in petroleum ether at 30-35° for 24 h (40%) [769]. 

OH Preparation by reaction of chlorine with 4,4 -dihydroxy-benzophenone in acetic Cl Cl acid [326]. 

Preparation from 2,4 -diamino-2, 4-dihydroxy-benzophenone with hydrochloric acid in refluxing dilute ethanol (72%) [286]. 

Obtained by reaction of a 30% aqueous solution of hydrogen peroxide with 5,5 -thiobis(2,4-dihydroxy-benzophenone) in acetic acid. The mixture was then heated on a steam bath for 6 h [1474],... 

Obtained in two steps first, treatment of 3,4 -dihydroxy-benzophenone with sodium hydride (2.2 equiv) in DMF, then reaction of ethyl iodide (1.1 equiv) with the sodium salt previously obtained, at -10° (50%) [1528]. 

CTA Cellulose triaeetate (ASTM) see also CT, DHBP 2,4-Dihydroxy benzophenone (WTR)... 

---