212623-28-4

Upstream product

• 123-11-5 4-methoxy-benzaldehyde 
• 212623-27-3 3,5-diacetyl-4-(4-methoxyphenyl)-1,4-dihydropyridine 
• 74-88-4 methyl iodide 

Downstream Products

• 212623-31-9 1-[3-Acetyl-6-hydroxy-4-(4-methoxy-phenyl)-1-methyl-1,9a-dihydro-4H-benzo[4,5]furo[2,3-b]pyridin-4a-yl]-ethanone 

Relevant academic research and scientific papers

Novel synthesis of polyfunctionalized 1,4,4a,9a-tetrahydro-1-aza-9-oxafluorenes by unexpected cycloaddition of 4-(4-methoxyphenyl)-1,4-dihydropyridines and p-benzoquinone

A surprising acid-catalysed cycloaddition reaction occurs between 3,5-diacetyl-4-(4-methoxyphenyl)-1,4-dihydropyridine (4) and p-benzoquinone in dioxane/HClO4 (5%) yielding novel polyfunctionalized 1,4,4a,9a-tetrahydro-1-aza-9-oxafluorenes (9) as exclusive products. On the other hand the corresponding 4-unsubstituted 1,4-dihydropyridine (1) is oxidized by p-benzoquinone. Novel structures are characterized by standard spectroscopy and, furthermore, confirmed by acetylation. The different reactivity of the 4-substituted and 4-unsubstituted derivatives is dicussed on the basis of semiempirical MNDO calculations and redox potentials.