The ortho-Alkylation of Phenols¹

Phenol Derivatives

“…Currently 2,6-dialkylphenols, in particular, are produced using this process, which was developed independently by both Bayer [84] and Ethyl Corp. [85] in 1954. An overview of the reaction is given in the publications [86][87][88][89].…”

“…Therefore, if a high yield of the ortho isomer is desired, it is necessary to work at the lowest possible temperature (which must nevertheless be sufficiently high for rapid ether cleavage) and at a high olefin concentration, and to stop the reaction at the optimum point in time. If lower olefins are used as alkylating agents, it is necessary to work under pressure in order to achieve a high olefin concentration [86], [87]. To avoid dealkylation and isomerization in the subsequent distillative workup, the aluminum phenolate catalyst is deactivated by, for example, addition of water or sodium hydroxide to the reaction mixture after the end of the reaction [91].…”

“…Thus under kinetically controlled conditions 2,4-ditert-butylphenol and phenol react to form predominantly 2-tert-butylphenol [92]. In the case of dealkylation in the presence of aluminum phenolate, ortho-tert-alkyl groups are eliminated more rapidly than those in the para position [87], [93].…”

Antioxidants

“…This group is effective and easily made at moderate cost by the ortho-alkylation of phenol by olefins (e.g., isobutene) using an aluminum alkoxide alkylation catalyst [43] (! Acylation and Alkylation, Section 2.1.5).…”

Reaction of 3‐methyl phenol with tung oil

“…[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] In this paper, more detailed discussion about the amount of 3-methyl phenol reacted with tung oil, the bond position in 3-methyl phenol and so on are made from the results of IR, NMR, and HLC analyses.…”