Abstract: The present invention provides a process for the preparation of a chelant or chelating agent complex of the formula L•B•M. L is an amino acid derivative including two optically active amino acids are linked via a (CH2)n group, wherein the (CH2)n group is attached to a nitrogen of each optically active amino acid, the optically active amino acid may be the same or different; and wherein n is an integer from 1 to 10; B is a base; and M is a metal. The process comprises the steps of (i) providing a reaction mixture comprising L and B and having a pH of less than 7.5; (ii) contacting the reaction mixture with M to provide a first complex mixture; and (iii) contacting the first complex mixture with a further amount of B to provide a second complex mixture. The second complex mixture can further be sequentially contacted with further amounts of M and further amounts of B. Alternatively, the second complex mixture can be heated.

Abstract: This invention provides a process for the preparation of a complex of the formula L·B·M wherein (a) L is of the formula (R1)(R2)N—(CH2)n—N(R3)(R4), wherein each of (R1)(R2)N and N(R3)(R4) is an optically active amino acid, which may be the same or different; and wherein n is an integer from 1 to 10, (b) B is a base and (c) M is a metal, the process comprising the steps of (i) providing a reaction mixture comprising L and B and having a pH of less than 7.5; (ii) contacting the reaction mixture with M to provide an first complex mixture; and (iii) contacting the first complex mixture with a further amount of B to provide a second complex mixture.

Abstract: This invention provides improvements in certain processes for alkylating amino acids whereby yields based on amino acid are improved. More specifically, the invention provides a process for the preparation of amino acid derivatives in free acid or salt form, in which the nitrogen atoms of two or more amino acid molecules are linked by a hydrocarbyl or substituted hydrocarbyl group, which comprises reacting, in an aqueous medium at a pH in the range 7-14, a compound of the formula X-A-Y where X and Y are halo atoms which may be the same or different and A is a hydrocarbyl or substituted hydrocarbyl group, in which X and Y are attached to aliphatic or cycloaliphatic carbon atoms, with an amino acid (or salt thereof), wherein the reaction is carried out in the presence of dissolved cations of an alkaline earth metal or of a transition metal and/or wherein the unreacted amino acid is recovered and recycled.

Abstract: This invention provides improvements in certain processes for alkylating amino acids whereby yields based on amino acid are improved. More specifically, the invention provides a process for the preparation of amino acid derivatives in free acid or salt form, in which the nitrogen atoms of two or more amino acid molecules are linked by a hydrocarbyl or substituted hydrocarbyl group, which comprises reacting, in an aqueous medium at a pH in the range 7-14, a compound of the formula X—A—Y where X and Y are halo atoms which may be the same or different and A is a hydrocarbyl or substituted hydrocarbyl group, in which X and Y are attached to aliphatic or cycloaliphatic carbon atoms, with an amino acid (or salt thereof), wherein the reaction is carried out in the presence of dissolved cations of an alkaline earth metal or of a transition metal and/or wherein the unreacted amino acid is recovered and recycled.

Abstract: This invention provides improvements in certain processes for alkylating amino acids whereby yields based on amino acid are improved. More specifically, the invention provides a process for the preparation of amino acid derivatives in free acid or salt form, in which the nitrogen atoms of two or more amino acid molecules are linked by a hydrocarbyl or substituted hydrocarbyl group, which comprises reacting, in an aqueous medium at a pH in the range 7-14, a compound of the formula X-A-Y where X and Y are halo atoms which may be the same or different and A is a hydrocarbyl or substituted hydrocarbyl group, in which X and Y are attached to aliphatic or cycloaliphatic carbon atoms, with an amino acid (or salt thereof), wherein the reaction is carried out in the presence of dissolved cations of an alkaline earth metal or of a transition metal and/or wherein the unreacted amino acid is recovered and recycled.

Abstract: This invention provides improvements in certain processes for alkylating amino acids whereby yields based on amino acid are improved. More specifically, the invention provides a process for the preparation of amino acid derivatives in free acid or salt form, in which the nitrogen atoms of two or more amino acid molecules are linked by a hydrocarbyl or substituted hydrocarbyl group, which comprises reacting, in an aqueous medium at a pH in the range 7--14, a compound of the formula X--A--Y where X and Y are halo atoms which may be the same or different and A is a hydrocarbyl or substituted hydrocarbyl group, in which X and Y are attached to aliphatic or cycloaliphatic carbon atoms, with an amino acid (or salt thereof), wherein the reaction is carried out in the presence of dissolved cations of an alkaline earth metal or of a transition metal and/or wherein the unreacted amino acid is recovered and recycled.