Diphenylmethanols

The effects of some methoxy substituents were determined for the reaction with diphenylmethanol at a range of sulphuric acid concentrations in acetic acid containing 0.55 M water at 25 °C (Table 92)366. The logarithms of the rate coeffi-... 

The following undergraduate laboratory procedure for the synthesis of diphenylmethanol using the Grignard methodology (Box 4.1) according to Scheme 4.1 is given as an illustrative example where the above analysis is employed. 

Box 4.1 Experimental protocol for synthesizing diphenylmethanol via a Grignard reaction. 

Scheme 3.55 ((i )-Thiolan-2-yl)diphenylmethanol ligand for addition of ZnEt2 to... 

Condensation of a diphenylmethanol derivative, such as Michler s hydrol (6.159), with a reactive aryl component under acid conditions (the hydrol synthesis) also provides a leuco base. The dye 6.163 (Cl Acid Green 50) is made by reacting Michler s hydrol with R acid (2-naphthol-3,6-disulphonic acid) and oxidising the resulting leuco compound (Scheme 6.30). 

Scheme 6.5 Reaction scheme for benzophenone hydrogenation. DPM diphenylmethanol CHPK cyclohexyl phenyl ketone CHPM cyclohexylphenylmethanol DCHK dicyclohexyl ketone and DCHM dicyclohexylmethanol. (Reproduced from Reference [34].)...

Stance, oxidation of diphenylmethane with 0.1 mol % 5a and 10 equiv. of 30% H2O2 under ambient conditions afforded a 1 1 mixture of diphenylmethanol and benzophenone in 34% yield after 16 h. When heated to 80 °C for 5 h, the reaction is driven to the formation of benzoquinone in 87% yield. Cu(OAc)2 and Cu (salen) also afforded benzoquinone under identical conditions, but were found to be less effective than 5a. 

In the examples of Figures 18.8 and 18.9 the probe molecule is diphenyl-methanol, and it reacts with ferf-butoxyl radicals as shown in Scheme 18.3. Usual probe concentrations were between 50 and 200 mM. Figure 18.8 shows a representative trace for the formation of the ketyl radical from diphenylmethanol (i.e., the same formed by photoreduction of benzophenone), the only detectable species in the system. Figure 18.8 shows how the value of growth, given by the slope of the plots, changes with substrate (1,7-octadiene) concentration, as predicted by Eq. 18. 

Figure 18.8. Evaluation of kg ovth for 1,7-octadiene. (A) 0.067 M (B) 0.54 M, and (C) 0.94 M. Concentration of diphenylmethanol (used as a probe) 0.133 M. Only 12 representative points out of 50 used for the calculations have been plotted in each case. Insert Oscilloscope trace for 1,7-octadiene 0.94 mP [Reproduced with permission from H. Paul, R. D. Small, Jr., and J. C. Scaiano, J. Am. Chem. Soc. 1978, 100, 4520. Copyright 1978 American Chemical Society.]...

Gerrard [11] had shown earlier that the slow addition of 0.5 mole of thionyl chloride to a mixture of pyridine (1.0 mole) and hydroxy compounds (n-butyl, M-amyl, or ethyl lactate—0.1 mole) gives pyridine hydrochloride and good yields of the sulfite (see Eq. 4). Primary and secondary alcohols with an aromatic nucleus in the a-position give chlorides in the absence of catalysts [12], For example, diphenylmethanol gives the chloride even at —78°C. Sulfites derived from tertiary alcohols are not known. The further addition of thionyl chloride converted the sulfite to the chlorosulfinate (see Eq. 5 and Table I). 

It gives diphenylmethanol, mp 68°, almost quantitatively with Na2S03 soln and with 10% sulfuric acid, it is cleaved to phenol benz (Ref 2)... 

Diphenyl methyl n if rate, C0H5.Cri( ONO 2).C 6ii 5 mw 229.23, N 6.11% highly refracting, colorless ctysts (from petr eth), mp 36.7—37.2° bp 40—60°, unstable at RT slowly decomp with evolution of brn fumes on heating to 140—50° it smoothly decompd to henzophenone its soln in methyl cyanide was hydrolyzed to diphenylmethanol by shaking with saturated bicarbonate soln for several hrs. It is too unstable to be isolated by ordinary methods, but can be obtd in soln, by heating under reflux dipheny line thy 1 chloride Sc an excess of powdered Ag nitrate in dry ether. The ethereal soln was evaporated in a vacuum (See Refs)... 

C18H 8N4Og, derive of Diphenylmethanol were not found in the literature thru 1966... 

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