3.5- Dimethylphenoxide

Lithium 2,6 dimethylphenoxide, from 2,6-dimethylphenol, 46,115 methylation of, to form 2,6,6-tri-methyl 2,4 cyclohexadienone, 46, US... 

Homoleptic phenoxido complexes of the composition [Re(L)4] where L = 2,6-diisopropylphenoxide or 2,6-dimethylphenoxide have been prepared by the reaction of [ReCl4(THF)2] with the lithium salts of the ligands. The molecular geometry is square planar and the metal center is well protected from above and below the Re04 plane by the isopropyl groups and protects the complex from reactions with alkynes, whereas such a reaction and the formation of [Re(OC6H3-2,6-Me2)4(RC=CR)] adducts (R = Me, Eth, Ph) has been observed for the dimethyl derivative of the phenoxide. ... 

The Kp of cryptated potassium phenoxide is higher (about 4 times) for 2,6 dimethylphenoxide compared to 3,5 dimethylphenoxide. 

The simple phenoxides M2(OPh)10 (M = Nb, Ta) similarly behave as dimers in solution,187 while there is H NMR and IR spectroscopic evidence for the terminal and bridging aryloxides.188 With the more sterically demanding 2,6-dimethylphenoxides M(OAr)s, physical and spectroscopic data are consistent with their being monomeric. 

B. 2,6,6-Trimethyl-2,4-cyclohexadienone. In a nitrogen-filled dry box, 25.0 g. of lithium 2,6-dimethylphenoxide (0.195 mole) is transferred to an oven-dried, thick-walled Pyrex bomb tube (650 x 19 mm.). The bomb tube is stoppered with a rubber stopper fitted with a drying tube, removed from the dry box, and 75 ml. of methyl iodide (170 g., 1.20 moles) (freshly distilled from calcium hydride) is quickly pipetted into the bomb under a dry nitrogen stream. The bomb is cooled in a dry-ice bath and sealed with an oxygen torch. After warming to room temperature, the bomb is shaken to disperse the salt cake and placed in a bomb furnace which has been preheated to 135° (Note 7). 

Titration of a portion of the salt with 0.1 A hydrochloric acid to methyl orange end-point shows the salt to be 97-103% lithium 2,6-dimethylphenoxide. 

Methylthio-l, 2-dithiolium cations attack sodium phenoxide in the 2-position13,20 and sodium 2,6-dimethylphenoxide in the 4-position.31... 

The interaction of chloro- and (2,6-dimethylphenoxy)-triorganostannanes with tris(dimethylamino)sulfonium (TAS) chloride or 2,6-dimethylphenoxide in acetonitrile yields the corresponding homo- 30a-32a, 33-35 and mixed-ligand 36-38... 

An Sjuyl-type (S l ) mechanism has been proposed in the synthesis of poly(2,6-dimethyl-l,4-phenylene ether) through the anion-radical polymerization of 4-bromo-2,6-dimethylphenoxide ions (204) under phase-transfer catalysed conditions269. Ions 204 are oxidized to give an oxygen radical 205. The propagation consists of the radical nucleophilic substitution by 205 at the ipso position of the bromine in 204 (equation 144). The anion-radical 206 thus formed eliminates a bromide ion to form a dimer phenoxy radical 207 (equation 145). A polymeric phenoxy radical results by continuation of this radical nucleophilic substitution. 

A range of aryloxides exists. With 2,6-dimethylphenoxide, six-coordinate Y(OR)3(thf)3 (and dimeric [Y(OR)3(thf)]2 with five- coordination) are formed replacement of methyl by phenyl substituents leads to the isolation of the 2,6-diphenylphenolates [Ln(OC6H3Ph2-2,6)3] (Ln = La, Ce, Pr, Nd, Gd, Ho, Er, Ln, Y), which have monomeric structmes with the lanthanide slightly out of the O3 plane, but with some additional ring-metal interactions. [Ln(OC6H3Ph2-... 

A reaction in which perchloryl fluoride functions as an ambident electrophile, somewhat analogous to Neeman s oxofluorination, was discovered by Kende and MacGregor on passing FCIOj into a suspension of sodium 2,6-dimethylphenoxide in pentane or toluene at 0°. Workup and chromatography gave 2,6-dimethylphenol, 2,6-dimethylbenzoquinone, 2,2, 6,6 -tetramethyl-4,4 -diphenoquinone and, in about 20% yield, a new compound characterized as the dimer (3) of 6-fluoro-2,6-dimethyl-... 

Potassium 2,6-di-f-butylphenoxide, 234—237 Potassium dichromate, 337 Potassium 2,6-dimethylphenoxide, 235 Potassium ferricyanide, 192, 331 Potassium hexacyanodinickelate, 212 Potassium hydroxide, 238 Potassium 2-methylphenoxide, 235 Potassium nitrosodisulfonate, 7, 8, 238 Potassium periodate, 243 Potassium permanganate, 337 Potassium persulfate, 238-239 Potassium phenoxide, 235 Potassium phthalimide, 67 Prednisone-BMD, 261, 262 Al4,16.pregnadiene-20-ones, 324 5oPregnane-3,20-dione, 327, 328 50f-Pregnane-3,20-dione 3-dimethyl acetal, 327, 328... 

Unfortunately the condensation failed with certain a-halo ketones, for example -bromoacetone. Successful alkylation of this ketone would provide a useful route to methyl ketones. Brown et al.4 then explored use of a number of other bases the most satisfactory proved to be 2,6-di-/-butyl phenoxide. This is a weak base and a-haloketones are stable in its presence for a considerable length of time. The presence of the bulky alkyl substituents also appears to be highly favorable. Thus the following yields of n-butyrophenone were obtained from the reaction of phenacyl bromide and triethylborane with the bases indicated potassium phenoxide (2%), potassium 2-methylphenoxide (29%), potassium 2,6-dimethylphenoxide (75%), and potassium 2,6-di-f-butylphenoxide (98%). 

A. Lithium 2,6-dimethylphenoxide. In a 300-ml. flask, equipped with a magnetic stirrer and a reflux condenser and flushed with nitrogen, are placed 150 ml. of toluene (freshly distilled from sodium), 1.40 g. (0.202 mole) of lithium metal (Note 1) and 25.0 g. (0.205 mole) of resublimed 2,6-dimethylphenol. The mixture... 

---