Abstract: Stable aqueous leucoindigo solution comprising an aromatic amine in the form of aniline or aniline and N-methylaniline, wherein said leucoindigo is in the form of an alkali metal salt; wherein the concentration of the aromatic amine is below 40 ppm determined according to ISO 14362-1:2017(E); and wherein the concentration of the leucoindigo salt is in a concentration range of from 10 to 45% by weight based on the total weight of the solution, and wherein the stability of the solution is measured at a temperature of 23° C.; or wherein the concentration of the leucoindigo salt is in a concentration range of from 45 to 65% by weight based on the total weight of the solution, and wherein the stability of the solution is measured at a temperature of 60° C.

Abstract: Stable aqueous leucoindigo solution comprising an aromatic amine in the form of aniline or aniline and N-methylaniline, wherein said leucoindigo is in the form of an alkali metal salt; wherein the concentration of the aromatic amine is below 40 ppm determined according to ISO 14362-1:2017(E); and wherein the concentration of the leucoindigo salt is in a concentration range of from 10 to 45% by weight based on the total weight of the solution, and wherein the stability of the solution is measured at a temperature of 23° C.; or wherein the concentration of the leucoindigo salt is in a concentration range of from 45 to 65% by weight based on the total weight of the solution, and wherein the stability of the solution is measured at a temperature of 60° C.

Abstract: Method of making an aqueous aniline-free or aniline-free and N-methylaniline-free leucoindigo solution from an aqueous leucoindigo solution comprising aniline or aniline and N-methylaniline, the concentration of aniline or aniline and N-methylaniline being determined according to ISO 14362-1:2017(E), wherein said leucoindigo is in the form of an alkali metal salt, the method comprising at least steps (A) to (C): (A) providing a liquid stream comprising said aqueous leucoindigo solution comprising said amine(s); (B) providing a purification stream; (C) bringing into contact said liquid stream with said purification stream.

Abstract: Aqueous leucoindigo solution comprising an aromatic amine in the form of aniline or aniline and N-methylaniline, wherein said leucoindigo is in the form of an alkali metal salt; wherein the concentration of the aromatic amine is below 40 ppm determined according to ISO 14362-1:2017(E); and wherein the concentration of the leucoindigo salt is in a concentration range of from 15 to 45% by weight based on the total weight of the solution, and wherein the solution is stable at a temperature of 23° C.; or wherein the concentration of the leucoindigo salt is in a concentration range of from 45 to 65% by weight based on the total weight of the solution, and wherein the solution is stable at a temperature of 60° C.

Abstract: The invention relates to a process for the preparation of an ?-amino carbonyl compound by reacting an imine starting material with a suitable electrophile in the presence of a base. This process has the advantage that the imine starting materials can be prepared from glyoxylic acid esters or glyoxylic acid ester derivatives and ?-hydrogen containing primary amines, which are usually cheap and readily available. These imine starting materials can usually be prepared with a high yield and/or almost without the formation of any side products.