The present invention relates to a process for purifying ethylenediamine (EDA) by distillation, wherein the process comprises the steps a) and b). In step a), a mixture (G1) comprising water, EDA and N-methylethylenediamine (N-MeEDA) is fed into a distillation apparatus (D1), and the major part of the water comprised in the mixture (G1) is separated off overhead at a pressure of greater than 4.8 bara. From the bottom of (D1), the water-enriched mixture (G2) is fed into a distillation apparatus (D2) in step b). At the top of (D2), the major part of the N-MeEDA is distilled off. The stream (S3) obtained from the bottom of (D2) comprises EDA, with the components water and N-MeEDA comprised in the mixture (G1) having been largely or completely removed. Further distillation steps can optionally be carried out in order to obtain pure EDA, for example when diethylenetriamine (DETA) is additionally comprised in the mixture (G1). If ammonia is additionally comprised in the mixture (G1), an ammonia removal is preferably additionally carried out before carrying out the step a) in the process of the invention.

The present invention relates to a process for purifying ethylenediamine (EDA) by distillation, wherein the process comprises the steps a) and b). In step a), a mixture (G1) comprising water, EDA and N-methylethylenediamine (N-MeEDA) is fed into a distillation apparatus (D1), and the major part of the water comprised in the mixture (G1) is separated off overhead at a pressure of greater than 4.8 bara. From the bottom of (D1), the water-enriched mixture (G2) is fed into a distillation apparatus (D2) in step b). At the top of (D2), the major part of the N-MeEDA is distilled off. The stream (S3) obtained from the bottom of (D2) comprises EDA, with the components water and N-MeEDA comprised in the mixture (G1) having been largely or completely removed. Further distillation steps can optionally be carried out in order to obtain pure EDA, for example when diethylenetriamine (DETA) is additionally comprised in the mixture (G1). If ammonia is additionally comprised in the mixture (G1), an ammonia removal is preferably additionally carried out before carrying out the step a) in the process of the invention.

Provided is a method of making ethylenediaminetetraacetic acid (EDTA) comprising the steps: (a) providing a reaction mixture (a) comprising ethylenediamine (EDA) and glycolonitrile (GN), wherein reaction mixture (a) comprises 0% to 0.1% by weight, based on the weight of reaction mixture (a), of any base having pKa of the conjugate acid (PKaH) of 13 or higher; (b) causing or allowing reaction mixture (a) to react to form a dinitrile (DN) compound; (c) bringing the DN into contact with aqueous solution of a base having pKaH of 11 or higher, and causing or allowing the resulting mixture to react to form a diacid compound (DA); (d) causing or allowing the DA to react, either sequentially or simultaneously, with additional GN to form products (Pd); (e) causing or allowing products (Pd) to react with a base having pKaH of 11 or higher, to form EDTA. Also provided is a composition comprising a diacid/dinitrile compound (DADN) wherein each —R has the structure:

##STR00001##

Provided is a method of making ethylenediaminetetraacetic acid (EDTA) comprising the steps: (a) providing a reaction mixture (a) comprising ethylenediamine (EDA) and glycolonitrile (GN), wherein reaction mixture (a) comprises 0% to 0.1% by weight, based on the weight of reaction mixture (a), of any base having pKa of the conjugate acid (PKaH) of 13 or higher; (b) causing or allowing reaction mixture (a) to react to form a dinitrile (DN) compound; (c) bringing the DN into contact with aqueous solution of a base having pKaH of 11 or higher, and causing or allowing the resulting mixture to react to form a diacid compound (DA); (d) causing or allowing the DA to react, either sequentially or simultaneously, with additional GN to form products (Pd); (e) causing or allowing products (Pd) to react with a base having pKaH of 11 or higher, to form EDTA. Also provided is a composition comprising a diacid/dinitrile compound (DADN) wherein each —R has the structure:

##STR00001##

Reaction pathways and conditions for the production of nitrogen-containing chelators, such as a glycine derivative, as described herein. In particular, the present disclosure describes a process for the production of a nitrile intermediate by reacting a tetra-amino compound with an aldehyde and a hydrogen cyanide to form the nitrile intermediate. The nitrile intermediate may then be further processed to produce the chelators at a high yield and/or a high purity.

Reaction pathways and conditions for the production of nitrogen-containing chelators, such as a glycine derivative, as described herein. In particular, the present disclosure describes a process for the production of a nitrile intermediate by reacting a tetra-amino compound with an aldehyde and a hydrogen cyanide to form the nitrile intermediate. The nitrile intermediate may then be further processed to produce the chelators at a high yield and/or a high purity.

Reaction pathways and conditions for the production of nitrogen-containing chelators, such as a glycine derivative, are described herein. In particular, the present disclosure describes a process for the production of a nitrile intermediate by reacting a tetra-amino compound with an aldehyde and a hydrogen cyanide to form the nitrile intermediate. The nitrile intermediate may then be further processed to produce the chelators at a high yield and/or a high purity.

Reaction pathways and conditions for the production of nitrogen-containing chelators, such as a glycine derivative, are described herein. In particular, the present disclosure describes a process for the production of a nitrile intermediate by reacting a tetra-amino compound with an aldehyde and a hydrogen cyanide to form the nitrile intermediate. The nitrile intermediate may then be further processed to produce the chelators at a high yield and/or a high purity.

Reaction pathways and conditions for the production of nitrogen-containing chelators, such as a glycine derivative, are described herein. In particular, the present disclosure describes a process for the production of a nitrile intermediate at a high yield and/or purity. This process includes reacting a dinitrile compound with an aldehyde and a hydrogen cyanide to form the nitrile intermediate. The nitrile intermediate may then be further processed to produce the chelators at a high yield and/or a high purity.

Reaction pathways and conditions for the production of nitrogen-containing chelators, such as a glycine derivative, are described herein. In particular, the present disclosure describes a process for the production of a nitrile intermediate at a high yield and/or purity. This process includes reacting a dinitrile compound with an aldehyde and a hydrogen cyanide to form the nitrile intermediate. The nitrile intermediate may then be further processed to produce the chelators at a high yield and/or a high purity.