Process for making iminodiacetic acid compounds from monoethanolamine substrates

[0097]Examples 13–16 and 21 illustrate electrochemical displacement deposition of copper onto a metal sponge support. The same examples also illustrate the use of a chelating agent during such a deposition.

[0098]In a particularly preferred method for the deposition of copper onto a metal support, electrochemical displacement deposition is conducted under basic conditions followed by electrochemical displacement deposition under acidic conditions. Preferably, the metal support is free of surface oxidation at the time of the plating. However, in instances where the metal support has an oxidized surface (i.e., when the support has been exposed to air (even while under water) for 6 or more months), it is particularly preferable to pre-treat the support with a reducing agent. For example, the support may be stirred in a sodium borohydride solution, which preferably comprises a solution having a pH of at least about 10 and at least about 1 gram of sodium borohydride per 25 grams of metal sup

[0107]Examples 17–19 and 23 illustrate the use of electroless plating to deposit copper onto the surface of a metal support.

c. Other Copper-containing Catalysts

[0108]In another embodiment of this invention, the dehydrogenation catalyst does not comprise a copper-containing active phase deposited at the surface of a metal support (i.e., there is no discrete copper deposited on or coating the surface of the catalyst). Rather, the copper is mixed (preferably in the form of an alloy) with other metals which provide desirable properties to provide a catalyst active phase. In this embodiment, from about 10% to about 85% (more preferably from about 50% to about 85%, even more preferably from about 60% to about 80%, and still more preferably from about 60% to about 75%) by weight of the catalyst is copper. Preferably, the catalyst is in the form of a metal sponge. In a particularly preferred embodiment, the catalyst comprises greater than about 1% by weight nickel, tin, or a combination thereo

Example 1

Making Disodium Iminodiacetic Acid in 3 Steps, Beginning with the Cyanomethylation of 2-aminoethanol with Glycolonitrile

[0142]2-aminoethanol (9 g; 0.15 mol) was introduced into a 100 ml round-bottom flask (3 neck, 14 / 20 joints) containing a magnetic stirrer and fitted with a 60 ml addition funnel and an adapter for N2. The mixture was stirred and cooled in an ice bath to 2° C. An aqueous solution of glycolonitrile (HOCH2CN) (50% by weight; 17 g; 0.15 mol) was added dropwise over 10 minutes during which the temperature in the reactor never exceeded 14° C. After stirring in the ice bath for 15 minutes, the reaction was allowed to warm to room temperature and stirred for an additional 2 hours. Analysis by NMR indicated that the reaction was complete with a solution of 2-(N-cyanomethylamino)ethanol being formed.

[0143]The 2-(N-cyanomethylamino)ethanol solution prepared above was placed into a 100 ml Hastelloy-C autoclave. A warm (about 60° C.) aqueous solution of NaOH (50% by wei