Abstract: The present invention relates to a process for removing dissolved metal ions from an onium hydroxide and/or salt solution, including providing a weak acid ion exchange medium; providing a solution comprising magnesium ions; forming a magnesium-loaded ion exchange medium by contacting the ion exchange medium with the solution comprising magnesium ions; contacting the magnesium-loaded ion exchange medium with an onium hydroxide and/or salt solution containing a first quantity of dissolved metal ions, wherein at least a portion of the dissolved metal ions are removed from the onium hydroxide and/or salt solution; and collecting the onium hydroxide and/or salt solution after the contacting, wherein the solution collected contains a second quantity of dissolved metal ions smaller than the first quantity. The onium hydroxide and/or salt may be tetramethylammonium hydroxide and/or salt, and the metal content may be reduced to about 1 part per billion or less by the process.

Abstract: The present invention relates to a process for removing dissolved metal ions from an onium hydroxide and/or salt solution, including providing a weak acid ion exchange medium; providing a solution comprising magnesium ions; forming a magnesium-loaded ion exchange medium by contacting the ion exchange medium with the solution comprising magnesium ions; contacting the magnesium-loaded ion exchange medium with an onium hydroxide and/or salt solution containing a first quantity of dissolved metal ions, wherein at least a portion of the dissolved metal ions are removed from the onium hydroxide and/or salt solution; and collecting the onium hydroxide and/or salt solution after the contacting, wherein the solution collected contains a second quantity of dissolved metal ions smaller than the first quantity. The onium hydroxide and/or salt may be tetramethylammonium hydroxide and/or salt, and the metal content may be reduced to about 1 part per billion or less by the process.

Abstract: In one embodiment the present invention is a process for recovering an onium hydroxide from a cation exchange material having onium cations adsorbed thereto which comprises (A) contacting said cation exchange material with an aqueous solution of a base selected from alkali metal hydroxides and ammonium hydroxide to form an onium hydroxide, and (B) recovering an aqueous solution of the onium hydroxide. In another embodiment, the present invention relates to a process for recovering an onium hydroxide from a solution containing an onium compound such as an onium hydroxide and/or onium salt, including contacting the solution with a cation exchange material so that at least a portion of onium cations from the onium compound are adsorbed by the cation exchange material; contacting the cation exchange material having the onium cations adsorbed thereto with an aqueous solution of an inorganic base to form an onium hydroxide; and recovering the onium hydroxide solution.

Abstract: Disclosed is a method of producing p-aminobenzoylglutamic acid which comprises electrochemically reducing p-nitrobenzoylglutamic acid and/or p-hydroxyaminobenzoylglutamic acid using a cathode of a palladium metal or palladium alloy in an aqueous solution at a pH value of 3 or less.The method produces the objective p-amino compound in good yields and in high current efficiencies, and is advantageous for an industrial method.

Abstract: N-[2'-methyl-4'-aminopyrimidyl-5'-]methyl-4-methyl-5-.beta.-hydroxyethyl-th iothiazolone(2) is electrochemically oxidized to produce vitamin B.sub.1 in the anode side and simultaneously 2-methyl-4-amino-5-cyanopyrimidine is reduced to produce 2-methyl-4-amino-5-aminomethylpyrimidine in the cathode side. Both anode and cathode sides are separated from each other by at least one sheet of cation exchange membrane.