Kibardina, L. K. published the artcileAzomethines Based on Pyridoxal-Derived Aromatic Aldehydes, Application In Synthesis of 140-28-3, the publication is Russian Journal of General Chemistry (2018), 88(1), 41-47, database is CAplus.
The reaction of pyridoxal with 2,4-dihydroxybenzaldehyde in a hydrochloric acid solution gave 1-(5-formyl-2,4-dihydroxyphenyl)-7-hydroxy-6-methyl-1,3-dihydrofuro[3,4-c]pyridin-5-ium chloride. Treatment of the latter with sodium hydride in ethanol afforded a free aldehyde, 2,4-dihydroxy-5-(7-hydroxy-6-methyl-1,3-dihydrofuro[3,4-c]pyridin-1-yl)benzaldehyde in 85% yield. A series of azomethines I [R = (CH2)3NMe, Ph, 4-H2NC6H4, etc.] and imidazolidines II [R1 = Me, Bn] was obtained by reacting the obtained aldehyde with various amines and diamines.
Russian Journal of General Chemistry published new progress about 140-28-3. 140-28-3 belongs to catalysis-chemistry, auxiliary class Benzenes, name is N1,N2-Dibenzylethane-1,2-diamine, and the molecular formula is C16H20N2, Application In Synthesis of 140-28-3.
Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia