Unprecedented Halogenation of Biginelli Compounds of Salicyldehyde

Abstract

Unprecedented results are obtained from bromination of the normal/non-bridged and abnormal/bridged Biginelli compound of salicyldehyde. Bromination with 2,4,4,6-tetrabromocyclohexa-2,5-dienone yields a bridged monobromo-derivative and a bridged dibromo-derivative, respectively, whereas bromination with bromine and acetic acid gives a mixture of those two products in each case. Bromination with N-bromosuccinimide gives a third product, namely a tribromo-derivative, in addition to those two products. Iodination of both the substrates using iodine monochloride (Wijs solution) furnishes a bridged monoiodo-derivative only.

GRAPHICAL ABSTRACT

Keywords:

• Bicyclic compounds
• Biginelli compounds
• bromination
• 2,4,4,6-tetrabromocyclohexa-2,5-dienone
• Wijs solution

ACKNOWLEDGMENT

The financial assistance of the University Grants Commission in the form of minor research project is gratefully acknowledged.

Notes

^a time: 45 minutes; ^b time: 48 hours.