Methyl Salicylate → 2-Hydroxybenzoic acid 2-(2-hydroxybenzoyl)hydrazide

Beteiligte Stoffe

Reaktionsschritte

152 parts by weight salicyclic acid hydrazide was heated with 152 parts by weight salicylic-acid methyl ester and 3 parts by weight boron trioxide in 230 parts by weight paraffin (viscosity at 60° C.: 100 m Pa s) to 140° to 150° C. while stirring vigorously. Methanol produced during the reaction was distilled off by a column. After about 3 hours, the reaction was completed. The now viscous reaction mixture was cooled down to 50° to 60° C., treated with alcohol (methanol or ethanol) and the mixture was stirred very vigorously at about 50° to 60° C. The yellow-colored alcohol phase was decanted from the viscous paste and the process was repeated until discoloration was complete. After separating the washing alcohol, drying in a vacuum at about 100° C. was performed. 460 parts by weight of a colorless viscous paste was obtained, consisting of 230 parts by weight N,N'-bis(salicyloyl)hydrazine (85% yield) and 230 parts by weight paraffin. By dissolving the paraffin with methylene chloride and boiling-out the solid matter with methanol, N,N'-bis(salicyloyl)hydrazine with a melting and decomposition range of 305° to 310° C. was obtained.

Herkunft & Nachweise