Sumitomo Chemical Company, Limited

Daiei Chemical Co., Ltd.

Sumika Fine Chemical Company, Ltd.

Yuzo Maegawa

Shinichi Yachigo

Tamaki Ishii

Haruki Okamura

Yukoh Takahashi

Tatsuo Kaneoya

Eizo Okino

Hiroki Yamamoto

Yasuhiro Nishida

Norio Kotera

Takashi Miyaoka

Masatoshi Uegaki

Takashi Omura

Yasuyoshi Ueda

Fujio Masuko

Shinzaburo Masaki

Makoto Nakamura

Takeo Fujii

Kiyoyasu Hashimoto

Masakatsu Yoshimura

Akira Fukasawa

Masanobu Terao

Masatoshi Takahashi

Pure 1,4-dihydroxy-2-arylnaphthoate is prepared in high yield by allowing 1,4-dihydroxy-2-naphthoic acid to react with triarylphosphite in the presence of an acid catalyst selected from organic and inorganic acids and crystallizing from a mixed solvent consisting essentially of lower alcohols and water until 1,4-dihydroxy-2-naphthoic acid is isolated and is further purified by crystallization from a mixed solvent consisting essencially of lower alcohols, water and extraction solvent, i.e., alkyl-substituted aromatic hydrocarbons or halogen-substituted aliphatic or aromatic hydrocarbons.

Process for producing 1,4-dihydroxy-2-arylnaphthoate

Pure 1,4-dihydroxy-2-arylnaphthoate is prepared in high yield by allowing 1,4-dihydroxy-2-naphthoic acid to react with triarylphosphite in the presence of an acid catalyst selected from organic and inorganic acids and crystallizing from a mixed solvent consisting essentially of lower alcohols and water until 1,4-dihydroxy-2-naphthoic acid is isolated and is further purified by crystallization from a mixed solvent consisting essentially of lower alcohols, water and extraction solvent, i.e., alkyl-substituted aromatic hydrocarbons or halogen-substituted aliphatic or aromatic hydrocarbons.

A stabilized resin composition comprising a resin, a piperidine derivative represented by the formula (III) ##STR1## wherein R.sub.1 is a hydrogen atom or an alkyl group having 1 to 3 carbom atoms; R.sub.2 is a hydrogen atom or an alkyl group having from 1 to 2 carbon atoms; and R.sub.3 and R.sub.4 are each independently an alkyl group having 1 to 12 carbon atoms, a phenol-type antioxidant and a sulfur-containing antioxidant. The composition simultaneously meets heat resistance, oxidation resistance and light resistance requirements.

Process for producing piperidine derivative and stabilized resin

2,4-Dichloro-3-alkyl-6-nitrophenol, which is a precursor of 2,4-dichloro-3-alkyl-6-aminophenol useful for the production of a cyan coupler to be used with a sensitive material in the field of a photography in color, is industrially advantageously produced by (a) nitration of 2,4,5-trichloro-3-alkylbenzene, followed by hydrolysis of the resulting 2,4,5-trichloro-3-alkyl-6-nitrobenzene, or (b) hydrolysis of 2,4,5-trichloro-3-alkylbenzene-6-sulfonic acid or a salt thereof, followed by nitration of the resulting 2,4-dichloro-3-alkylphenol-6-sulfonic acid or a salt thereof, the starting material usable for these processes being 4-alkylbenzenesulfonic acid or a salt thereof, which is easily available.

Process for producing 2,4-dichloro-3-alkyl-6-nitrophenol

A stabilizer for synthetic resins containing as an effective ingredient a hindered piperidine compound represented by the general formula: ##STR1## wherein R.sub.1 represents a C.sub.1 -C.sub.18 alkyl group, R.sub.2 represents a hydrogen atom or a C.sub.1 -C.sub.4 alkyl group, n represents an integer of 1 to 12, and C.sub.n H.sub.2n represents a straight-chain or branched alkylene group.

Stabilizer for synthetic resins

Piperidine derivatives represented by the general formula (1) ##STR1## (wherein R.sub.1 is a hydrogen atom, an alkyl group of 1 to 3 carbon atoms or an acyl group of 2 to 18 carbon atoms; and k, m and n each are independently an integer of 1 to 3), a process for producing said derivatives, and stabilizers for organic substances containing said derivatives as an active component.

Piperidine derivatives, production process therefor, and stabilizers for

A method for purifying 1-aminoanthraquinone which comprises previously subjecting a crude 1-aminoanthraquinone to a removal treatment of inorganic impurities so that their content is reduced to not more than 4 wt. % as converted to ash basis or to a removal treatment of iodine-consuming reductive inorganic impurities so that their content is reduced to not more than 2 wt. % as converted to consumed iodine basis, and then rectifying the 1-aminoanthraquinone.

Method for purifying 1-aminoanthraquinone

The present invention relates to a piperidine derivative represented by the general formula (I), ##STR1## wherein R.sub.1 and R.sub.2 independently represent a hydrogen atom or a C.sub.1 -C.sub.3 alkyl or C.sub.2 -C.sub.20 acyl group, R.sub.3 represents a hydrogen atom or a C.sub.1 -C.sub.20 alkyl, C.sub.6 -C.sub.20 aryl, C.sub.7 -C.sub.20 aralkyl or C.sub.2 -C.sub.20 acyl group, and l represents 1 to 3, and a stabilizer for organic substances containing said piperidine derivative as an effective ingredient.

Piperidine derivatives, their production and use as stabilizers

The present invention relates to a piperidine derivative represented by the general formula (I), ##STR1## wherein R.sub.1 is a uni- or divalent carboxylic acid residue, R.sub.2 is a hydrogen atom or a C.sub.1 -C.sub.3 alkyl or C.sub.1 -C.sub.18 acyl group, l is an integer of 1 to 3 and n is 1 or 2, its production and a stabilizer for organic substances containing it as an effective ingredient.

A high melting, high boiling organic compound is easily and stably purified by continuously supplying the molten organic compound to a rectification zone under a subatmospheric pressure and continuously distilling off and recovering vapors from the top of the rectification zone, while continuously withdrawing bottoms containing higher boiling impurities and/or involatile impurities than the desired compound from a reboiling zone at the bottom of the rectification zone to the outside of rectification system by means of a barometric leg, without any pretreatment of removing lower boiling impurities therefrom before the rectification, and without disturbing a pressure balance in the rectification system.

Purification of compounds having high melting point

A process for producing 2-hydroxynaphthalene-3-carboxylic acid comprising reacting carbon dioxide with a homogeneous liquid mixture comprising an alkali metal salt of .beta.-naphthol, .beta.-naphthol and a specific alkylbenzene is disclosed.

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Osaka, Japan

Yuzo Maegawa