Ube Industries, Inc.

Katsuhiko Mizutare

Keigo Nishihira

Masaoki Matsuda

Kozo Fujii

Susumu Tahara

Shuji Tanaka

Takafumi Hirakawa

Ken Ikuno

Katsumasa Harada

Akio Matsushita

Noriaki Iwase

Taku Nakamura

Masayoshi Oku

Masahiro Kondo

Tsuyoshi Ueyama

Keig Nishihira

Disclosed is a method for preparing 2-mercaptothiazole, which comprises adding a dithiocarbamate salt represented by the formula (1): ##STR1## wherein M is a cation, to a chloroacetaldehyde solution in the presence of an acid.

Method for preparing 2-mercaptothiazole

Disclosed is a process for preparing 1-ethyl-5-hydroxy-pyrazole, which comprises reacting an alkyl 3-alkoxy-acrylate represented by the following formula (1): ##STR1## wherein R.sup.1 and R.sup.2 are the same or different from each other and each represent a lower alkyl group, and in the formula represents either cis- or trans-configuration, with ethylhydrazine in an amount of 1- to 10-fold mole based on 1 mole of the alkyl 3-alkoxyacrylate in a weakly basic aqueous solvent.

Process for preparing-1-ethyl-5-hydroxypyrazole

A pivaloylacetic acid ester is prepared at a high yield by decarbonylating a pivaloylpyruvic acid ester in gas or liquid phase in the presence of an inorganic oxide catalyst which comprises aluminum in an amount of 10% by weight or more in terms of aluminum oxide, and preferably is substantially free from heavy metals, for example, Fe, Cu, Ni, Mn, Cr, Mo and Co, and exhibits a high catalytic activity and chemical stability.

Method of producing pivaloylacetic acid ester

An N-hydroxycarbamate compound of the formula ROCONHOH in which R is C.sub.1-8 alkyl, C.sub.3-12 cycloalkyl, aryl or aralkyl group, is produced by reacting a carbonic acid diester of the formula ROCOOR in which R is as defined above, with hydroxylamine in the presence of a basic substance, for example, an alkali metal hydroxide or alkoxide.

Method of producing an N-hydroxycarbamate compound

A process for preparing a diester of carbonic acid which comprises bringing carbon monoxide into contact with an ester of nitrous acid in a vapor phase at a pressure greater than atmospheric pressure in the presence of a solid catalyst having (a) a platinum group metal or a compound thereof and (b) at least one metal compound of a metal selected from the group consisting of iron, copper, bismuth, cobalt, nickel and tin; carried on a carrier.

Process for preparing a diester of carboxylic acid

There is provided a process for the continuous preparation of a diester of oxalic acid, which comprises a first step of reacting carbon monoxide with an ester of nitrous acid in the gaseous phase; a second step of condensing the gaseous reaction mixture to separate a non-condensed gas from a condensed liquid containing the diester of oxalic acid; a third step of introducing the non-condensed gas of the second step to a regeneration column, thereby contacting it with a gas containing molecular oxygen and an alcohol, and recycling the resulting gas containing an ester of nitrous acid to the reactor of the first step; a fourth step of distilling out an alcohol containing a diester of carbonic acid formed as a by-product of the first step and obtaining a liquid diester of oxalic acid; and a fifth step of introducing the distillate of the fourth step to a hydrolysis column thereby hydrolyzing the diester of carbonic acid in the gas and recycling the alcohol as an alcohol source for the third step.

Process for continuous preparation of diester of oxalic acid

There is provided a process for the continuous preparation of a diester of oxalic acid which comprises a first step of reacting carbon monoxide with an ester of nitrous acid in the gaseous phase; a second step of condensing the gaseous reaction mixture to separate a non-condensed gas from a condensed liquid containing the diester of oxalic acid; a third step of introducing the non-condensed gas of the second step to a regeneration column and thereby contacting it with a gas containing molecular oxygen and an alcohol to regenerate nitrogen monoxide in the non-condensed gas into an ester of nitrous acid so as to bring the concentration of nitrogen monoxide in the gas at the outlet of the column to a level of from 2 to 7% by volume; and a fourth step of recycling the gas of the third step containing the ester of nitrous acid and from 2 to 7% by volume of nitrogen monoxide to the reactor of the first step.

Process for continuously preparing a diester of oxalic acid

There is disclosed a process for continuously preparing ethylene glycol, which comprises (1) a first step of contacting a gas containing carbon monoxide and an ester of nitrous acid with a solid catalyst of platinum group metal series in the gaseous phase thereby to obtain a product containing a diester of oxalic acid, (2) a second step of condensing the product of the first step thereby to separate a non-condensed gas containing nitrogen monoxide formed by the catalytic reaction of the first step from a condensed liquid containing the diester of oxalic acid, (3) a third step of contacting the non-condensed gas of the second step with a gas containing molecular oxygen and an alcohol, and recycling the resulting gas containing an ester of nitrous acid to the first step, (4) a fourth step of contacting the condensed liquid of the second step containing the diester of oxalic acid and hydrogen with a catalyst for hydrogenation in the gaseous phase thereby to obtain a product containing ethylene glycol, (5) a fifth step of distilling the product of the fourth step thereby to distill out the alcohol and to obtain ethylene glycol, and (6) a sixth step of recycling the alcohol of the fifth step as an alcohol source for the third step.

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Ube, Japan

Katsuhiko Mizutare