摘要:
A process for preparing a diester of oxalic acid which comprises bringing carbon monoxide into contact with an ester of nitrous acid or with an alcohol and a nitrogen oxide or a hydrate of the nitrogen oxide in the gaseous phase in the presence of a solid catalyst containing metallic palladium or a salt thereof, a gas containing molecular oxygen being introduced into the reaction system in cases where said nitrogen oxide or a hydrate of the nitrogen oxide requires molecular oxygen together with the alcohol to form an ester of nitrous acid.
摘要:
A process for preparing a diester of oxalic acid which comprises bringing carbon monoxide into contact with an ester of nitrous acid or with an alcohol and a nitrogen oxide or a hydrate of the nitrogen oxide in the gaseous phase in the presence of a solid catalyst containing metallic palladium or a salt thereof, a gas containing molecular oxygen being introduced into the reaction system in cases where said nitrogen oxide or a hydrate of the nitrogen oxide requires molecular oxygen together with the alcohol to form an ester of nitrous acid.
摘要:
A process for preparing a diester of oxalic acid which comprises bringing carbon monoxide into contact with an ester of nitrous acid in the liquid phase, in the presence of metallic palladium or a salt thereof, preferably with introduction of a gas containing molecular oxygen into the reaction system, more preferably with further incorporation of an alcohol in the reaction system.
摘要:
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.
摘要:
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.
摘要:
A process for preparing a diester of a dicarboxylic acid having two more carbon atoms than the unsaturated hydrocarbon used as a starting material, which comprises subjecting an unsaturated hydrocarbon, carbon monoxide and an ester of nitrous acid to catalytic vapor phase reaction at a temperature of 50.degree. to 200.degree. C. in the presence of a platinum group metal or a salt thereof and a halogen compound.
摘要:
A process for preparing a diester of malonic acid which comprises reacting ketene and carbon monoxide with an ester of nitrous acid catalytically in the presence of metallic palladium or a salt thereof.
摘要:
There is disclosed a process for the preparation of a 2-alkyl-4-amino-5-aminomethylpyrimidine, which comprises subjecting a 2-alkyl-4-amino-5-formylpyrimidine to catalytic reaction with hydrogen and ammonia in the presence of a reduction catalyst.According to the process of this invention, the desired product can be obtained in much higher yield as compared with the processes known to the art.
摘要:
There are disclosed a 4-alkoxy-1,3-dioxane-5-carbonitrile which is a novel compound represented by the formula ##STR1## wherein R represents a lower-alkyl group, and which is useful as an intermediate for the synthesis of Vitamin B.sub.1, and a process for preparing the novel compound by subjecting a 3-alkoxy-2-propenenitrile to reaction with a formaldehyde in the presence of an acid catalyst.
摘要:
A process for preparing a 4-amino-5-dialkoxymethylpyrimidine derivative of the formula: ##STR1## which comprises reacting a propanenitrile derivative represented by the formula (I) or the novel compound represented by formula (II): ##STR2## with an amidine of the formula: ##STR3## wherein R.sup.1 to R.sup.6 are as defined in the specification. Also disclosed is a process for making the novel compounds of formula (II).