反应详情

34.4 g of a bisazomethine prepared from 2 mols of salicylaldehyde and 1 mol of m-xylylenediamine and having a melting point of 61°-63° C. are hydrogenated for 7 hours in 170 ml of isopropanol in an autoclave in the presence of 4 g of Raney nickel at 85° C. and under a pressure of 60 atmospheres. The catalyst is filtered off and the filtrate is concentrated in a rotary evaporator to give 35.8 g of crude product. 25.7 g are recrystallised from 77 ml of isopropanol and the bulk of the product separates out on cooling in a refrigerator. The precipitate is collected by filtration, washed off with cold isopropanol and dried in vacuo at 40° C., affording 11.0 g (41.8% of theory) of N,N'-bis-(2-hydroxybenzyl)-m-xylylenediamine with a melting point of 67°-68° C.

1. filtrationThe catalyst is filtered off
2. concentrationthe filtrate is concentrated in a rotary evaporator
3. customto give 35.8 g of crude product
4. custom25.7 g are recrystallised from 77 ml of isopropanol
5. temperatureon cooling in a refrigerator
6. filtrationThe precipitate is collected by filtration
7. washwashed off with cold isopropanol
8. customdried in vacuo at 40° C.