[3] The double cyanomethylation of β-alanine as starting material provides with methanal and alkali cyanides and subsequent hydrolysis of the intermediately formed bis-methyl cyanides followed by acidification with mineral acids β-ADA (N-(2-carboxyethyl)iminodiacetic acid) in yields of only 80%, but very high purity of 99.8%.

The cyanoethylation of iminodiacetic acid with 2-propenenitrile by a Michael addition provides the ethyl cyano compound, which produces after alkaline hydrolysis and acidification β-ADA with a total yield of 93.6% and purity of 99.9% .

In the analogue reaction with acrylic acid esters, 99.9% β-ADA are obtained after acidification in a total yield of 97.6%.

The most economical synthesis route is based on iminodiacetic acid, which is easily accessible by oxidizing diethanolamine and serves as a key raw material for the herbicide glyphosate.

[8] The contradictory assessment of the degradability of β-ADA, the weaker complex formation compared to the (rapidly biodegradable) methylglycine diacetic acid (MGDA, Trilon M) and the lower stability in wide temperature and pH ranges have substantially contributed to the breakthrough of MGDA as the most suitable substitute for EDTA.