JOC;1957;22;1435-8;Karasch & Joshi;Reactions of Hindered Phenols. I, Reactions of 4,4'-Dihydroxy-3,5,3',5'-tetra-tert-butyl Diphenylmethane.
http://www.geocities.com/botero56/JOC.1957.22.1435-8.Karasch_Joshi.pdf
"The base-catalyzed condensation of formaldehyde with IV is here carefully examined and is shown to give two different products depending upon the alcohol used as solvent."
(IV = 2,6-di-tert-butylphenol)
"The formation of VI in methanol and not in other alcohols (ethanol, 2-propanol, t-butyl alcohol) may be attributed to the higher acidity of methanol."
(VI = 4-hydroxy-3,5-di-tert-butylbenzyl methyl ether)
"It should be emphasized that oxygen must be rigidly excluded in all the base-catalyzed reactions of IV, otherwise there is a rapid condensation of IV to 3,5,3',5'-tetra-tert-butyldiphenoquinone VII."
Experimental:
"4-hydroxy-3,5-di-tert-butylbenzyl methyl ether (VI).
2,6-di-tert-butylphenol (5.2 g), 36% formaldehyde (5 ml) and absolute methanol (50 ml) were dissolved in a three-necked flask and a solution of potassium hydroxide (2 g in 2 ml water) was added under an atmosphere of nitrogen. The solution was refluxed for 30 minutes under a current of nitrogen. After cooling, the pale yellow crystalline product was collected (5.5 g, 82%) on a filter, and crystallized severeal times from methanol. Colorless plates were thus obtained which melted at 99.5°."
Okay, this is the methyl ether of the benzyl alcohol, dunno how stable that is or if it could be useful. Off hand, this etherification of the benzyl alcohol seems similar to the acylation mechanism in
Patent US5315018
Still, the authors claim in the beginning of the article:
"It was claimed by Bamberger (2a) that, in the presence of alkali, I reacts with formaldehyde at room temperature to give II. Above 30 years later, this observation was disputed by Granger. The latter investigator claimed that, under a variety of experimental conditions, I condenses with formaldehyde to give exclusively III. The authors, howevever, found no difficulties in preparing II by the Bamberger procedure, nor in preparing III by the procedure of Auwers."
(I = 2,6-dimethylphenol
II = 4-hydroxy-3,5-dimethylbenzyl alcohol
III = 4,4'-dihydroxy-3,3,5,5'-tetramethyl diphenylmethane)
(2a): E. Bamberger, Ber., 36, 2036 (1903)
Does anyone have this Bamberger-article handy?
