反应详情

温度

90 °C

37.2 g of 5-chloro-2-hydroxybenzoic acid hydrazide are dissolved in 200 ml of dimethylacetamide and 16 g of pyridine and 22 g of chloroformic acid ethyl ester are added simultaneously over the course of 30 minutes. The reaction mixture is subsequently heated to 90° C for 3 hours whilst stirring, cooled and poured onto 1 litre of ice water. The precipitate which has separated out slowly crystallises throughout. The N-(5-chloro-2-hydroxybenzoyl)-hydrazinecarboxylic acid ethyl ester thus obtained (Stabiliser No. 11) is isolated, washed with water and recrystallised from ethanol. Melting point 172° C.

1. temperaturecooled
2. customThe precipitate which has separated out slowly
3. customcrystallises throughout