反应详情

40.8 g of a bisazomethine prepared from 2 moles of salicylaldehyde and 1 mol of ethylenediamine and having a melting point of 127° C. are hydrogenated, at atmospheric pressure in a hydrogenation flask, in 200 ml of glacial acetic acid in the presence of 1.36 g of 10% platinum/charcoal catalyst at 25° C. After 12 hours, the catalyst is filtered off and used to hydrogenate a further 81.6 g of bisazomethine in 400 ml of glacial acetic acid. After 20 hours, the completely hydrogenated solution is separated from the catalyst and concentrated, together with the above filtrate, in a rotary evaporator. The solid residue is recrystallised from 700 ml of isopropanol, the mother liquor concentrated three times and the products are dried at 90° C. in vacuo, affording a total of 162.2 g of N,N'-bis-(2-hydroxybenzyl)-ethylenediamine diacetate which melts in the range of 120°-130° C.

1. filtrationthe catalyst is filtered off
2. waitAfter 20 hours
3. customthe completely hydrogenated solution is separated from the catalyst
4. concentrationconcentrated, together with the above filtrate, in a rotary evaporator
5. customThe solid residue is recrystallised from 700 ml of isopropanol
6. concentrationthe mother liquor concentrated three times
7. customthe products are dried at 90° C. in vacuo