| 摘要 |
Ortho- or para-monoalkylated phenols or 2,4- or 2,6-dialkylphenols can be produced from phenolic compounds in good yields and in the absence of isomers. The starting phenol which has at least two available ortho or para positions unsubstituted is converted to a t-alkylated phenol having at least one ortho or para position unsubstituted. The desired t-alkylated phenolic compound is reacted with an aldehyde having one to four carbon atoms and a secondary aliphatic or alicyclic amine. The reaction is conducted in the liquid phase with a stoichiometric amount of the phenolic compound and stoichiometric or excess of stoichiometric amounts of the aldehyde and the secondary amine. The reaction is conducted at a temperature in the range of about 0 DEG C., to about 100 DEG C. and the reaction produces an aminoalkylated t-alkylated phenol. The aminoalkylated phenol is contacted with hydrogen in the presence of a metal catalyst at a temperature of about 100 DEG C. to about 175 DEG C. at a hydrogen pressure not greater than 500 psi to produce monoalkylated, mono- or di-t-alkylated phenol or a dialkylated, mono-t-alkylated phenol in the ortho- and para- positions. The thus produced alkylated t-alkylated phenolic compound is contacted with an acid or an acid reacting substance to give the desired alkylated phenolic compound. These compounds are separated to produce ortho-monoalkylated, para-monoalkylphenol, 2,4-dialkylphenol and 2,6-dialkylphenol.
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