Abstract: The present invention discloses a process for the production of 2-methyl-1,4-naphthoquinone and its bisulfite adducts, comprising the following steps: a) oxidizing 2-methyl-naphthalene (2-MNA) to achieve an organic phase containing 2-methyl-naphthoquinone (2-MNQ) and 6-methyl-naphthoquinone (6-MNQ); b) subjecting said organic phase to treatment with an aqueous solution of a bisulfite salt to extract preferentially the 6-MNQ isomer from the organic phase; c) separating said organic phase from the aqueous phase; d) subjecting the organic phase of process step c) to a second bisulfitation step with an aqueous solution of a bisulfite salt, resulting in an organic phase containing 2-MNA and trace amounts of 2-MNQ and an aqueous phase containing 2-MSB and trace amounts of 6-MSB; e) optionally removing interfering bisulfite ions from the aqueous phase of process step c); f) raising the pH of the aqueous phase from step c) or e) to higher than 8.

Abstract: The present invention discloses a process for the production of 2-methyl-1,4-naphthoquinone and its bisulfite adducts, comprising the following steps: a) oxidizing 2-methyl-naphthalene (2-MNA) to achieve an organic phase containing 2-methyl-naphthoquinone (2-MNQ) and 6-methyl-naphthoquinone (6-MNQ); b) subjecting said organic phase to treatment with an aqueous solution of a bisulfite salt to extract preferentially the 6-MNQ isomer from the organic phase; c) separating said organic phase from the aqueous phase; d) subjecting the organic phase of process step c) to a second bisulfidation step with an aqueous solution of a bisulfite salt, resulting in an organic phase containing 2-MNA and trace amounts of 2-MNQ and an aqueous phase containing 2-MSB and trace amounts of 6-MSB; e) optionally removing interfering bisulfite ions from the aqueous phase of process step c); f) raising the pH of the aqueous phase from step c) or e) to higher than 8.

Abstract: The present invention discloses a process for the production of 2-methyl-1,4-naphthoquinone and its bisulfite adducts, comprising the following steps: a) oxidizing 2-methyl-naphthalene (2-MNA) to achieve an organic phase containing 2-methyl-naphthoquinone (2-MNQ) and 6-methyl-naphthoquinone (6-MNQ); b) subjecting said organic phase to treatment with an aqueous solution of a bisulfite salt to extract preferentially the 6-MNQ isomer from the organic phase; c) separating said organic phase from the aqueous phase; d) subjecting the organic phase of process step c) to a second bisulfidation step with an aqueous solution of a bisulfite salt, resulting in an organic phase containing 2-MNA and trace amounts of 2-MNQ and an aqueous phase containing 2-MSB and trace amounts of 6-MSB; e) optionally removing interfering bisulfite ions from the aqueous phase of process step c); f) raising the pH of the aqueous phase from step c) or e) to higher than 8.

Abstract: A method for purifying a Redox mediator used in a chemical process of oxidation of organic compounds. The desired purification is obtained by recovering the mediator in the form of a solution and heating this solution to evaporate the volatile impurities contained in it and to oxidize the non volatile impurities into compounds which precipitate and are extracted by filtration. The purification takes place before the mediator is regenerated in the electrolysis cell. This prevents the impurities contained in the mediator solution to negatively affect the operation of this cell.

Abstract: A method for purifying a Redox mediator used in a chemical process of oxidation of organic compounds. The desired purification is obtained by recovering the mediator in the form of a solution and heating this solution to evaporate the volatile impurities contained in it and to oxidize the non volatile impurities into compounds which precipitate and are extracted by filtration. The purification takes place before the mediator is regenerated in the electrolysis cell. This prevents the impurities contained in the mediator solution to negatively affect the operation of this cell.