Diphenylmethane, derivatives

Obtained by reaction of 2-hydroxy-4,4 -dimethoxybenzo-phenone with lead tetraacetate in acetic add at 100° for 5 h (21%) [1082]. 

Phenyl[2,3,4-trihydroxy-5-[(2,4 6-trihydroxyphenyl)methyl]phenyl]methanone 

Phenyl[2, 4-trihydroxy-5-[(4-hydroxy-2-methylphenyl)methyl]phenyl]methanone 

---

For uniformity with the stmctures given in the Colourindex the ammonium radical (9) is used for the amino-substituted xanthenes and the keto form for the hydroxy derivatives. The xanthene dyes may be classified into two main groups diphenylmethane derivatives, called pyronines, and triphenylmethane derivatives (eg, (4)), which are mainly phthaleins made from phthaUc anhydride condensations. A third much smaller group of rosamines (9-phenylxanthenes) is prepared from substituted ben2aldehydes. The phthaleins may be further subdivided into the following fluoresceins (hydroxy-substituted) rhodamines (amino-substituted), eg, (6) and mixed hydroxy/amino-substituted. 

Pyronines. Pyronines are diphenylmethane derivatives synthesized by the condensation of y -dialkylarninophenols with formaldehyde, followed by oxidation of tiie xantiiene detivative (12) to the coiiesponding xanthydiol (13) which in the presence of acid forms the dye (14). If R is methyl, the dye produced is... 

Diphenylmethane Base Method. In this method, the central carbon atom is derived from formaldehyde, which condenses with two moles of an arylamine to give a substituted diphenylmethane derivative. The methane base is oxidized with lead dioxide or manganese dioxide to the benzhydrol derivative. The reactive hydrols condense fairly easily with arylamines, sulfonated arylamines, and sulfonated naphthalenes. The resulting leuco base is oxidized in the presence of acid (Fig. 4). 

Diphenylmethane derivatives (e.g., bisacodyl) and anth-raquinones (e.g., senna) have a selective action on the nerve plexus of intestinal smooth muscle leading to enhanced motility. The onset of effect is rapid but the effects can be harsh (cramping), depending on the dose taken. Castor oil is another member of this class that is used less frequently. 

A clay mineral and/or its acid-treated products109,110 are used as color developers. A diphenylmethane derivative of structure 82 has been micro-... 

Low susceptibility to Florida reef fishes due to secondary metabolites (Paul and Hay 1986). Specimens of Carrie Bow Cay, Belize, produce a brominated diphenylmethane derivative (avrainvilleol), which significantly deters feeding by reef fishes (Hay et al. 1990)... 

B. Large-bowel irritant laxatives diphenylmethane derivatives... 

Stimulant laxatives increase intestinal motility thereby decreasing absorption of water and electrolytes. Included in this group are diphenylmethane derivatives and anthraquinones. 

OTC Alophen, Dulcolax, Fleet, Gentlax, Modane, Veracolate Chemical Class Diphenylmethane derivative... 

The diphenylmethane derivative 248 gives by double Rossing reactions the benzofurans 249579 (R = CH2COOEt). 

The question may arise whether diphenylmethane derivatives—e.g., bis-4-hydroxy-3,5-dimethoxyphenylmethane and diguaiacylmethane, are realistic lignin models. Pertaining to this study, the models are realistic if they occur in lignin in situ or if they are artifacts formed in any of the various alkaline pulping processes. 

From a practical viewpoint, perhaps diphenylmethane derivatives are formed at the extremities of lignin fragments in alkaline pulps. The derivatives might then react as shown in Scheme II, forming colored products such as AA, in which R represents the remainder of the lignin fragment. 

Benzylation of various aromatics with benzyl chloride also proceeds smoothly over 13% Nafion-silica to afford diphenylmethane derivatives in high yields237 (Table 5.18). Although deactivated aromatics (nitrobenzene, methyl benzoate) gave low (< 10%) yields, chlorobenzene reacted readily with complete conversion similar to naphthalene. Furthermore, the catalyst, after recovery, exhibited the same activity. 

Formylation of the less reactive phenol and anisole with CO in HF-BF3 was found to require at least stoichiometric amount of the acid for effective transformation (50 equiv. of HF, 2 equiv. of BF3, 50 bar CO, 45°C).445 Conversion increases with increasing reaction time but results in decreasing paralortho ratios suggesting a change from kinetic control to thermodynamic control and the reversibility of formylation. Furthermore, the amount of byproducts (mainly diphenylmethane derivatives) originating from reactions between substrates and products also increases. Additional studies in ionic liquids showed that imidazolium cations with increased chain lengths—for example, l-octyl-3-methylimidazolium salts—are effective in the formylation process. This was attributed to the enhanced solubility of CO in the ionic liquid medium. Tris(dichloromethyl)amine, triformamide, and tris (diformylamino)methane have recently been applied in the formylation of activated aromatic compounds in the presence of triflic acid at low temperature (— 10 to 20°C) albeit yields are moderate.446... 

Among the most popular privileged structures, historical representatives are arylethylamines (including indolylethylamines), diphenylmethane derivatives, tricyclic psychotropics and sulfonamides. Dihydropyridines [5], benzodiazepines, [2, 5], N-arylpiperazines, biphenyls and pyridazines [6] are more recent contributions. 

Sun, H. H., Paul, V. J., and Fenical, W., Avrainvilleol, a brominated diphenylmethane derivative with feeding deterrent properties from the tropical green alga Avrainvillea longicaulis, Phytochemistry, 22, 743, 1983. 

Laxatives in this group exert an irritant action on the enteric mucosa (A). Consequently, less fluid is absorbed than is secreted. The increased filling of the bowel promotes peristalsis excitation of sensory nerve endings elicits enteral hypermotility. According to the site of irritation, one distinguishes the small-bowel irritant castor oil from the large-bowel irritants anthraqui-none and diphenylmethane derivatives (for details see p.178). 

Indirect methylation of reactive phenols is sometimes accomplished by condensation of two molecules of the phenol with one molecule of formaldehyde. The resulting diphenylmethane derivative may be reduced with zinc and sodium hydroxide or cleaved by alkali to the methylated phenol. A modification of this procedure involves dimethylaminomethyl-ation of the phenol followed by hydrogenolysis of the dimethylamino-methyl group. ... 

---