Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 fift