Synthesis 2009(14): 2349-2356  
DOI: 10.1055/s-0029-1216849
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

gem-Dibromomethyl Aromatics: Efficient Aldehyde Equivalents in the Knoevenagel-Doebner Reaction

John Kallikat Augustine*a,b, Yanjerappa Arthoba Naikb, Subba Poojaria, Nagaraja Chowdappaa, Bailur Sheena Sherigarab, Kummara Areppaa
a Syngene International Ltd., Biocon Park, Plot Nos. 2 & 3, Bommasandra IV Phase, Jigani Link Road, Bangalore 560099, India
Fax: + 91(80)2808 3150; e-Mail: john.kallikat@syngeneintl.com;
b Department of Chemistry, Kuvempu University, Shankaraghatta Post, Shimoga 577451, India
Further Information

Publication History

Received 3 March 2009
Publication Date:
29 May 2009 (online)

Abstract

A valuable variation of the Knoevenagel-Doebner reaction for the efficient synthesis of cinnamic esters is described. This reaction provides cinnamic esters in a single step from gem-dibromomethyl aromatics, which otherwise require the hydrolytic conversion of gem-dibromides into aldehydes, and demonstrates the use of an alternative reagent for noncommercial and expensive aldehydes. Further, the reaction of gem-dibromomethyl aromatics with malonic acid and di-tert-butyl dicarbonate for the one-pot synthesis of tert-butyl cinnamates is also described.