Impure wet-process phosphoric acid is treated with urea by known processes to produce relatively pure urea phosphate which is then treated with oxalic acid to give solid urea oxalate and purified phosphoric acid product. The urea oxalate is either treated with ammonia to give urea and ammonium oxalate or it is pyrolyzed to produce urea and oxamide.

There is provided a process for the preparation of esters of oxalic acid comprising reacting at a temperature of between about 20.degree. and 200.degree. C. a copper (II) compound having the formula Cu(OR)X, where R is alkyl having from 1 to 8 carbon atoms and X is chlorine or bromine, with carbon monoxide in the presence of a catalyst selected from the group consisting of palladium salts, metallic palladium and zero valent palladium complexes.

A method for making a diester of oxalic acid which comprises oxidatively carbonylating an alcohol having 1 to 10 carbon atoms with carbon monoxide and with oxygen at a pressure from 1 to 700 bars and at a temperature from 20.degree. C. to 250.degree. C. in a reaction phase comprising said alcohol having dissolved therein a catalyst system consisting essentially of, as cations, ions of palladium(II) and copper ions in a molar ratio of at least 0.2 and, as anions, halide ions and carboxylate ions ...

In a process for preparing a diester of oxalic acid by the vapor phase catalytic reaction of carbon monoxide with an ester of nitrous acid in the presence of a catalyst composed of a solid carrier and a catalyst component supported on the carrier, the improvement wherein said catalyst component is composed of (a) a platinum-group metal or a salt thereof, and (b) at least one metal selected from the group consisting of Mo and Ni, or a salt thereof.

The invention concerns specific new oxalic acid diarylamides which are characterized by an asymmetrical substitution with regard to the central oxalic amide moiety of the formula and by substitution with one or two alkoxy, alkenyloxy, aralkenyloxy or acyloxy groups. Definite additional substituents may be present. The compounds are valuable ultraviolet stabilizers.

Processes are disclosed for bleaching pulp with ozone in an environmentally friendly bleaching plant. The processes include removing a first filtrate from the pulp, bleaching the treated pulp with ozone, washing the bleached pulp with a washing liquid to provide a washed bleached pulp and a second filtrate including oxalic acid, recycling the second filtrate to the pulp prior to the bleaching step, and transferring the first filtrate to the bleached pulp.

The present invention relates to a process for preparing oxalic acid and esters of oxalic acid. More particularly, this invention relates to a catalytic process for preparing oxalic acid and esters of same by the oxidative reaction, in a liquid phase, of carbon monoxide and water or alcohols with oxygen in the presence of redox systems. The catalyst systems used in accordance with this invention comprises a redox catalyst consisting essentially of a salt of Pd (II) and salts of a metal more elec...

This invention relates to new forms of amphotericin B which comprise amphotericin B, an acid anion, and calcium ion. These new forms of amphotericin retain the activity of amphotericin and have the particular advantage of being soluble in acidic or alkaline solutions.

A new process is described for the preparation of oxalic acid esters and amides of general formula (I) ##STR1## wherein Z designates an --OR or --NR.sup.1 R.sup.2 group, wherein R represents substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, or aryl-alkyl, R.sup.1 is hydrogen or substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, or aryl-alkyl, R.sup.2 represents substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, or aryl-alkyl, or R.sup.1 and R.sup.2 taken toge...

An oxalic acid or oxalate composition and method of treatment of warm blooded animals including humans and pets is provided which includes at least one therapeutically effective form of oxalic acid or oxalate selected, for example, from oxalic acid in a free acid, ester, lactone or salt form, oxalates including sodium oxalate, a nutritional supplement containing oxalic acid or oxalate, oxalic acid dihydrate, anhydrous oxalic acid, oxamide, oxalate salts, natural or processed foods including mold...