2,2 diphenylmethane

—In the preparation of certain compounds by condensation sis the result of the elimination of chlorine and hydrogen, an aluminium-mercury couple gives better results than aluminium chloride. It is probable that a little aluminium chloride is first formed by the action of the metal on the organic halogen compound the presence of mercury makes the aluminium more active. 

Oxidation of Diphenylmethane to Benzophenone (SECTIONS 435, 487, 572).—In the identification of organic substances they are frequently oxidized and the products isolated. The 

If an oil separates, rub it against the side of the beaker with a glass rod. A form of benzophenone which crystallizes with difficulty, is produced as the result of the oxidation of diphenylmethane. If a sample of benzophenone is available a trace can be used to seed the oil if it does not crystallize when rubbed sharply against the beaker. Determine the melting-point of the crystals. Benzophenone melts at 48°. 

—In oxidizing compounds with chromic anhydride, a slight excess is used over that required for the oxidation. Two molecules of the anhydride furnish three atoms of oxygen. If the compound which is insoluble in water is to be oxidized, acetic acid is often used as a solvent. As chromic anhydride is difficultly soluble in glacial acetic acid, it is first dissolved in a little water and acetic acid added to the solution. Oxidation takes place 

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By-products are formed in both preparations thus in the former, anthracene, and o- and p-dibenzylbenzenes are present in the fraction of high boiling point. Diphenylmethane is more conveniently obtained by the interaction of benzyl chloride and benzene in the presence of aluminium amalgam ... 

The series of compounds biphenyl, diphenylmethane, and fluorene is an interesting one. The following diagrams give the partial rate factors ... 

These partial rate factors have been recalculated from the experimental data of Dewar and Urch. Their reported values for diphenylmethane are not seriously discrepant with the values now given, but this is not so for the values for fluorene. As given, and copied in the literature, the values were /j = 2040 / = 60 fi = 944. There are consequent errors in table 8 and figs. 16 (reproduced as fig. 9. i of this volume) and 32 of ref. 22. 

The first three of a series of papers by Ridd and co-workers on Inductive and Field effects in Aromatic Substitution have appeared. Results of studies of the nitration of 4-phenylp5nidine and of 4-benzylpyridine in aqueous sulphuric acid were reported and use of the usual criteria (para 8.2) showed that in each case the conjugate acid was the species undergoing nitration. The values of where fm refers to the corresponding homocyclic compound (biphenyl or diphenylmethane) when plotted against r, the distance between the... 

Diphenylmethane is significantly more acidic than benzene and tnphenylmethane is more acidic than either Identify the most acidic proton in each compound and suggest a reason for the trend in acidity... 

Cm.OROCARBONSANDCm.OROHYDROCARBONS - BENZYL CTD ORIDE, BENZAL CTD ORIDE AND BENZOTRICm ORIDE] (Vol 6) Diphenylmethane 4,4pdiisocyanate [101-68-8]... 

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... 

Several alternative methods followed this early work. In one, aromati2ation is effected by treating the ketal of androstadienedione with the radical anion obtained from lithium and diphenyl in refluxing tetrahydrofuran. Diphenylmethane is added to quench the methyllithium produced from the... 

Benzophenone is produced by the oxidation of diphenylmethane (350). This free from chlorine (FCC) route is favored for perfume uses. The Friedel-Crafts reaction of benzene and benzoyl chloride in the presence of aluminum chloride is also possible this reaction may proceed in the absence of catalyst at a temperature of 370°C and pressure of 1.4 MPa (351). 

Diisocyanates or Polyisocyanates. The thiol end groups of the hquid polysulfides are quite reactive with isocyanates (eq. 3). Typical chisocyanates, such as 1,3-toluene chisocyanate (m-TDl) and diphenylmethane-4,4 -diisocyanate (MDl), ate effective in curing hquid polysulfides. Using hquid polysulfides in-... 

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). 

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