Analyses by GC–MS and GC–MS–MS of the hantzsch synthesis products using hydroxy- and methoxy-aromatic aldehydes

EI mass spectra of products of the dihydropyridine Hantzsch synthesis using hydroxy and methoxy aldehydes as starting materials are reported. The reaction products (C-4 hydroxy- and methoxyphenyl-1,4-dihydropyridines and chromeno[3,4,c]-pyridines) were derivatized with N-methyl-N-(trimethylsilyl)-trifluoracetamide to be analyzed by gas chromatographic techniques. Fragmentation pathways for 1,4-dihydropyridines and chromeno-pyridines are proposed. The study provides (mainly through MS–MS technique) useful data for the confirmation of the structure of the compounds and also is a valuable tool for further analytical purposes to follow both photostability and reactivity studies with free radicals for these types of compounds.