Mitsubishi Petrochemical Company Limited

Mitsubishi Chemical Corporation

Research Association for Utilization of Light Oil

Seiko Epson Corporation

Mitsubishi Yuka Fine Chemicals Co., Ltd.

Hiroshi Iwane

Takahiro Sugawara

Makoto Imanari

Makoto Takeda

Naoki Suzuki

Kimiko Kaneko

Takashi Hashimoto

Takatoshi Seto

Jun Takehara

Shuji Ichikawa

Hidekazu Miyagi

Satoshi Ohtaka

Shoichi Seo

Katufumi Kujira

Masatoshi Takagi

Yuzuru Sato

Masashi Suzuki

Masashi Inaba

Yuji Ohgomori

Kunimasa Takahashi

Tadamichi Aoki

Tadashi Ayusawa

Eiji Taniyama

Masaki Saito

Mitsugi Kataoka

Takahiro Yoneyama

Hiroshi Taniguchi

Katsufumi Kujira

Tomoya Sakata

Satoshi Imada

Takashi Tanaka

Shiro Inui

Hirotaka Ryutou

Yuji Ozawa

Masayuki Uchide

Noriko Wada

Teruo Mori

Katsufumi Kuzira

Toshihiko Yahata

Nobuyoshi Maruyama

Katsuhumi Kuzira

Kenichi Sugimoto

Akira Yoshida

Shiroh Inui

Kazuaki Isomura

Shin Kawano

Miwa Shirasaki

Disclosed is a method for purifying homocystine comprising treating crude homocystine with a base, a method for purifying homocystine comprising recovering homocystine by neutralizing an alkaline aqueous solution of crude homocystine with an acid, and a homocystine powder containing 1,000 ppm or less of a polysulfide.

Method for purifying homocystine

Homocystine is produced by heating methionine in the presence of sulfuric acid and a hydrogen halide.

Method for producing homocystine

A liquid crystal composition which shows an antiferroelectric smectic phase in a wide temperature range including room temperatures, and allows high speed operation at a low voltage. A liquid crystal composition comprising at least one kind of compound expressed as ##STR1## shows an antiferroelectric smectic liquid crystalline phase at room temperatures. In the above-mentioned formula, both R.sub.1 and R.sub.2 are alkyl groups, X.sub.1 is a bonding group, X.sub.2 and X.sub.3 are independently selected bonding groups, k, m and n are independently selected from 0 or the integer 1, Z is CF.sub.3 or CH.sub.3, A.sub.1 and A.sub.2 are groups independently selected from a six-membered ring optionally replaced with 0 to 2 nitrogen atoms, or a group in which 2 to 3 such six-membered rings of the same kind or different kinds are linked at the para positions directly or via one or more bonding groups, wherein one or more hydrogen atoms in one or more such rings is optionally replaced with either fluorine atom, methyl group or ethyl group.

Liquid crystal compositions

The present invention relates to a method of producing an aromatic carbonate by reacting an aromatic hydroxy compound, carbon monoxide and oxygen using as a catalyst a specified catalyst system containing palladium and cerium compounds. Specifically, the present invention relates to a method of producing an aromatic carbonate by reacting an aromatic hydroxy compound, carbon monoxide and oxygen in the presence of a catalyst containing the following compounds:

Method of producing aromatic carbonate

The present invention relates to a method of producing an aromatic carbonate by reacting an aromatic hydroxy compound, carbon monoxide and oxygen using a catalyst system for suppressing the production of aryl aromatic o-hydroxycarboxylate as a by-product. The catalyst system consists of the following compounds:

A process for producing 2,6-naphthalenedicarboxylic acid by oxidizing 2,6-dimethylnaphthalene by molecular oxygen in the presence of a catalyst including cobalt, manganese and bromine. The oxidation reaction is performed by using a 2,6-dialkylnaphthalene mixture of 2,6-dimethynaphthalene and a small amount of 2,6-diisopropylnaphthalene as a raw material. Thus, the desired 2,6-naphthalenedicarboxylic acid can be produced at a high yield.

Process for producing 2,6-naphthalenedicarboxylic acid

A process for purifying a crude naphthalenedicarboxylic acid containing impurities and coloring substances obtained by the oxidation of a di-substituted naphthalene, dispense with the use of a large amount of alkali or acid, and producing a naphthalenedicarboxylic acid having a high purity and good color effectively and in a high recovery is disclosed, which comprises dissolving the crude naphthalenedicarboxylic acid in a mixed solvent comprising an amine compound and an alcohol and conducting crystallization.

Process for purification of naphthalenedicarboxylic acid

A process for preparing pyruvate in high yield is disclosed, comprising reacting propylene glycol with molecular oxygen in an aqueous solution in the presence of a platinum catalyst containing a metallic component selected from the group consisting of lead, thallium, and cadmium while controlling the pH of the reaction mixture between 7 and 9. The crude pyruvate can be purified by treating with activated carbon in the presence of water.

Process for preparing pyruvate

Process for para-methylolating phenol compounds

A process for producing a polyhydroperoxy aromatic compound by oxidation of an aromatic hydrocarbon, e.g., 4,4'-diisopropylbiphenyl and 4,4'-diisopropylnaphthalene, with molecular oxygen is disclosed, in which the oxidation is carried out in the presence of a metal ion selected from cobalt, nickel, zinc and lead ions. Even in using a reaction apparatus made of an iron-containing metal generally employed in industry, a high conversion of secondary alkyl groups can be reached, and the desired polyhydroperoxy aromatic compound can be obtained in a high yield.

Process for producing polyhydroperoxy aromatic compound

A process for preparing 2,6-naphthalenedicarboxylic acid comprising oxidation reaction of 2,6-diisopropylnaphthalene or an oxidation product thereof with molecular oxygen in a solvent containing an aliphatic carboxylic acid in the presence of a catalyst comprising cobalt and manganese as heavy metals and a bromine compound is disclosed, in which said oxidation reaction is carried out in the presence of at least one nitrogen-containing compound selected from the group consisting of a pyridine compound, ammonia, a carboxylic acid ammonium salt, urea, a urea derivative, an amine, and a carboxylic acid amide. 2,6-Naphthalenedicarboxylic acid can be obtained at higher purity and in increased yield.

Process for preparing 2,6-naphthalenedicarboxylic acid

A process for preparing .alpha.-ketobutyric acid comprising contacting 1,2-butanediol with molecular oxygen in the presence of a platinum catalyst is disclosed. The process produces .alpha.-ketobutyric acid in high yield at low cost.

Process for preparing .alpha.-ketobutyric acid

An optically active compound represented by formula (I): ##STR1## wherein R.sup.1 represents an alkyl group having from 6 to 18 carbon atoms or an alkoxy group having from 6 to 18 carbon atoms; A represents ##STR2## or ##STR3## wherein ring ##STR4## represents a nitrogen-containing hetero-aromatic ring; n and m each represents 0 or 1; R.sup.2 represents an alkyl group having from 1 to 12 carbon atoms; and C* is an asymmetric carbon atom. The compound of formula (I) exhibits excellent physicochemical stability, a low temperature range for the chiral smectic C phase when used either alone or in combination with other compounds, and a rapid response.

Optically active compound

A process for preparing 4,4'-dihydroxybiphenyl comprising oxidizing 4,4'-diisopropylbiphenyl with molecular oxygen and decomposing the resulting oxidation product in the presence of an acid catalyst is disclosed, in which oxidation of 4,4'-diisopropylbiphenyl is carried out in the presence of ammonia or an ammonium salt. The oxidation product has an increased selectivity of 4,4'-diisopropylbiphenyl dihydroperoxide and, therefore, produces the desired product in high yield upon acid decomposition.

Process for preparing 4,4'-dihydroxybiphenyl

A process for preparing p-hydroxybenzyl alcohol or a derivative thereof comprising reacting a phenol and a formaldehyde source under a basic condition is disclosed, wherein the reaction is carried out in an alcoholic organic solvent in the presence of a crown ether. The process achieves high selectivity toward the para position without involving high cost.

Process for preparing p-hydroxybenzyl alcohol

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Ibaraki, Japan

Hiroshi Iwane