Salicylaldehyde Azine

Salicylaldehyde Azine 2,2′-Azinodimethyldiphenol; C₁₄H₁₂N₂O₂ = 240.3 (959-36-4)

Dissolve 0.30 g of hydrazine sulfate in 5 mL of water, add 1 mL of glacial acetic acid and 2 mL of a freshly prepared 20% v/v solution of salicylaldehyde in 2-propanol. Mix, allow to stand until a yellow precipate is formed. Shake with two quantities, each of 15 mL, of methylene chloride. Combine the organic layers and dry over anhydrous sodium sulfate. Decant or filter the solution and evaporate to dryness. Recrystallise from a mixture of 40 volumes of methanol and 60 volumes of toluene with cooling. Dry the crystals in vacuo.

Melting point, about 213°.

Chromatography Thin-layer chromatography (2.2.27) as prescribed in the test for hydrazine in the monograph Povidone (0685); the chromatogram shows only one principal spot.