反应详情

30.4 g of salicylic acid hydrazide are dissolved in 500 ml of dimethylacetamide and 34.8 g of salicylic acid chloride are added dropwise over the course of 70 minutes at 25° - 40° C. The yellow solution is stirred for 3 hours at room temperature and is then poured into 1 liter of water, whereupon white, fine crystals precipitate. The substance is filtered off, washed with water and dried in vacuo at 60° C. The product is purified by recrystallisation from ethylene gylcol monomethyl ether. The N,N'-bis-salicyloyl-hydrazine thus obtained (stabiliser No. 1), melts at 303° C.

1. filtrationThe substance is filtered off
2. washwashed with water
3. customdried in vacuo at 60° C
4. customThe product is purified by recrystallisation from ethylene gylcol monomethyl ether