2,5-dihydroxybenzohydrazide

Conditions: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 33.6 g of 2,5-dihydroxybenzoic acid hydrazide are dissolved in 150 ml of dimethylacetamide and 66.5 g of chloroformic acid octadecyl ester in 150 ml of dimethylacetamide, and 21 g of triethylamine, are added simultaneously over the course of 30 minutes. Thereafter the reaction mixture is warmed to 40° C for 3 hours whilst stirring, cooled and poured into 2 litres of water. The N-(2,5-dihydroxybenzoyl)-hydrazinecarboxylic acid octadecyl ester obtained (Stabiliser No. 8) forms a pulverulent precipitate which is isolated, washed with water, dried at 80° C and recrystallised from isopropanol. Melting point 163° C. cooled