Biginelli compounds (ethyl 4-substituted-2-oxo-1,2,3,4-tetrahydropyrimidine-6-carboxylates) prepared from cyclodehydration of ethyl acetoacetate, urea and aromatic (or aliphatic) aldehydes have been subjected to bromination using (i) Br2/CHCl3 (ii) Br2/AcOH and (iii) 2,4,4,6-tetrabromocyclohex-2-en-1-one (TBCO) separately. The last one viz., TBCO is found to be the best reagent in preparing the 6-dibromethyl derivative in terms of yield and green context.
2,4,4,6-Tetrabromocyclohex-2-en-1-one, Biginelli compounds, Dibromination, Bromine