Mitsui Petrochemical Industries, Ltd.

Yoshito Kurano

Michio Tanaka

Katsuo Taniguchi

Masayasu Ishibashi

Toshihiro Takai

Kazunori Takahata

Sanehiro Yamamoto

Masahiro Kondo

Naoya Sakamoto

Masato Kawamura

N-alkyl amino phenols, such as N-ethyl-m-amino phenol are produced in high yield and with high purity by reacting a divalent phenol, such as resorcinol, with an alkylamine, such as ethylamine, in the absence of catalyst and solvent, at a temperature of 120.degree.-210.degree. C. under elevated pressure in an inert gas atmosphere. In a first embodiment, the resulting reaction mixture is acidified to convert the N-alkylaminophenol to its water soluble salt and the resulting aqueous layer is separated from the oily layer. The aqueous layer is rendered alkaline to liberate N-alkylaminophenol as an oily layer. The N-alkyl-aminophenol oily layer is then separated from the aqueous layer and distilled. In an alternative embodiment, the reaction mixture resulting from the reaction between the divalent phenol and alkylamine is combined with an aqueous solution of an alkali to convert unreacted phenol to its water soluble salt while the product N-alkylaminophenol remains in an oily phase which is separated from the aqueous phase. An organic solvent is used as an extractant. The recovered N-alkylaminophenol organic solution is then distilled to recover N-alkylaminophenol. Purities of the recovered N-alkylaminophenol in excess of 95% can be achieved.

Method of producing N-alkylaminophenols

Process for preparing Biphenols

A process is disclosed which is capable of producing p,p'-biphenol of high purity by the dealkylation reaction of 3,3',5,5'-tetra-t-butyl-4,4'-dihydroxybiphenyl and which yet allows isobutene to be recovered in high yield. The process performs the dealkylation reaction of 3,3',5,5'-tetra-t-butyl-4,4'-dihydroxybiphenyl in the presence of an acid catalyst using as a solvent a saturated hydrocarbon having a boiling point of 190.degree. C. or above, an alicyclic hydrocarbon having a boiling point of 190.degree. C. or above, a hydrocarbon with an iodine value of no more than 1, sulfolane, or a mixture of these solvents. Also disclosed is a process for producing p,p'-biphenol from a mixture of 2,6-di-t-butyl-phenol and 3,3',5,5'-tetra-t-butyl-4,4'-diphenoquinone or from a mixture of 2,6-di-t-butylphenol, 3,3',5,5'-tetra-t-butyl-4,4'-diphenoquinone and 3,3',5,5'-tetra-t-butyl-4,4'-dihydroxybiphenyl. In this process, the synthesis of 3,3',5,5'-tetra-t-butyl-4,4'-dihydroxybiphenyl by the redox reaction between 2,6-di-t-butylphenol and 3,3',5,5'-tetra-t-butyl-4,4'-diphenoquinone and the production of p,p'-biphenol by the dealkylation reaction of 3,3',5,5'-tetra-t-butyl-4,4'-dihydroxybiphenyl are performed at one stage in the presence of both an acid catalyst and a solvent at a temperature of 120.degree.-280.degree. C.

Process for producing p,p'-biphenol

Process for producting alkyl group-substituted aromatic hydrocarbons

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Iwakuni, Japan

Yoshito Kurano