3.5- Dimethyl-4-methoxyphenol

Guaiacic acid [4,4 -(2,3-dimethyl-l-butene-(l,4-diyl)-bis-(2-methoxyphenol)] [500-40-3J M... 

A novel application of a phenyl aryldiazosulfone was found by Kessler et al. (1990). l-[4-(7V-Chlorocarbonyl-7V-methylamino)phenyl]-2-(phenylsulfonyl)diazene (6.18) is an acid chloride with a potential diazonio group. The above authors showed that in organic solvents (THF, etc.) this compound reacts easily, as expected, with nucleophiles (HNu), e.g., with aliphatic, aromatic, or heterocyclic amines, with cystine dimethyl ester, or with 4-methoxyphenol at the carbonyl function, yielding... 

The palladium-catalyzed substitution of the less reactive racemic ethyl 3-cyclohexe-nyl carbonate could, in a similar fashion, be completed with dimethyl malonate, p-methoxyphenol, or phthalimide as nucleophiles, with satisfactory ee (Eq. 11.38) [55]. These reactions, when irradiated for 1 min with temperatures up to 100 °C, delivered yields (91-96%) and ee values (94—95%) identical with those performed in... 

The reaction of 2,2-dimethyl-4,6-dioxo-l,3-dioxane (Meldrum s acid 394) and its analogues with 3-dialkylaminophenols has been used to prepare some fluorescent 7-dialkylamino-4-hydroxycoumarins (Scheme 127) (77M499). The substituted malonic acid (395) or its dehydration product is a possible intermediate, since it is known that diaryl-malonic esters are accessible from phenols and the 1,3-dioxane. 3-Methoxyphenol yields the pyrano[3,2-c]benzopyran-2,5-dione (396) in this reaction, presumably by annelation of another ring on to initially formed 4-hydroxy-7-methoxycoumarin. 

A unique feature of this procedure is the selective monode-methylation of the dimethyl ether. The scope of this reaction is illustrated6 in part by the preparation in high yield of p-methoxyphenol, guaiacol, and phloroglucinol dimethyl ether from the respective fully O-methylated compounds. An exception is pyrogallol trimethyl ether which affords pyrogallol 1-monomethyl ether in high yield.6... 

To a solution of 23.1 g flake KOH in 250 mL hot EtOH there was added 61.8 g 2,3-dimethyl-4-methoxyphenol followed by 60 g methyl iodide. This was held under reflux for 12 h, then stripped of solvent under vacuum. The residue was dissolved in 1.2 L H20, acidified with HC1, and extracted with 3x200 mL CH2C12. The combined extracts were washed with 3x100 mL 5% NaOH, and the solvent was removed under vacuum. The residue set up as an off-white mass of leaflets weighing 37.7 g after filtering and air drying. Recrystallization from MeOH gave 2,3-dimethyl-1,4-dimethoxybenzene as white solids, with a mp of 78-79 °C. Anal. 

For example, 3,4-dimethylphenol (7.35) is oxidized to 4,5-dimethyl-o-benzoquinone (7.36) with Fremy s radical (7.34) and sodium dihydrogen phosphate. The oxidation of the phenol 2-[(Z)heptadec-10 -enyl]-6-methoxyphenol (7.37) with Fremy s radical produced irisquinone (7.38) in 87% yield. 

The semi-methylation of resorcinol with dimethyl sulfate leads to m-methoxyphenol (45%). ... 

C15H22 1 -(1,5-dimethyl-4-hexenyl)-4-methy benzene 644-30-4 565.39 50.201 2 28772 C15H2402 2,6-di-tert-butyl-4-methoxyphenol 489-01-0 523.15 46.113 2... 

An alternate strategy involved anodic oxidation of /> 7ra-methoxyphenol TBDPS ether derivatives (LXXVIII). The resulting mixed 0-silyl 0-methyl bisketals (LXXIX) underwent selective monohydrolysis of the dimethyl ketal moiety [87]. Alternatively, desi-lylation of LXXIX with B114NF gave dimethyl monoketals of the opposite regiochemistry [Eq. (37)]. This work was in contrast to earlier studies on similar silyl ethers systems, wherein O-Si bond cleavage predominated during electrolysis [88]. 

Biphenyl Dimethyl methyl m-Methoxyphenol Stearic acid... 

Ethenyl-2-methoxyphenol (4-vinylguaiacol) 4-Hydroxy-2,5-dimethyl-3(2H)-furanone (furaneol) 3-Methyl-2-buten-1 -thiol Beta-Damascenone... 

When acyclic and cyclicl-alkenyl aminosulfoxonium salts were allowed to react with a base, p-silyloxy alkylidene carbenes were generated, which underwent a l,5-0,Si-bond insertion and 1,2-silyl migration to form 2,3-dihydrofurans <04JA485ft>. As can be seen in the scheme below, 2,3-dihydrofurans could also be formed from various 2,2-dimethyl-5-methoxy-carbonyloxy-3-pentyn-l-ols in the presence of p-methoxyphenol via a palladium-catalyzed cyclization reaction <04TL1861>. 

The mixture was added to 800 mL H20, and a little surface scum mechanically removed with a piece of filter paper. The solution was acidified with concentrated HCI, depositing 30.9 g of a tan solid. Recrystallization from H20 gave 2,3-dimethyl-4-methoxyphenol as white needles, with a mp of 95-96 deg C. Anal. (C9H1202) H C calcd, 71.06 found 70.20. The N-methyl carbamate was made by the treatment of a solution of the phenol (1 g in 75 mL hexane with 5 mL CH2CI2 added) with 2 g methyl isocyanate and a few drops of triethyl amine. The pale pink solids that separated were recrystallized from MeOH to give a product that had a mp of 141-142 deg C. Anal. (Cl 1H15N03) C,H,N. 

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