N-bromobutanimide → Methyl 3-bromomethylthien-2-ylglyoxylate

Participants

Reaction Steps

A solution of 135.7 g (0.73 mol) of methyl 3-methylthien-2-ylglyoxylate, 131.2 g (0.73 mol) of N-bromosuccinimide and 1.35 g of azobisisobutyronitrile in 1000 ml of carbon tetrachloride is refluxed for 3 hours. Thereafter, the mixture is filtered and the filtrate is evaporated down. The residue is taken up in diethyl ether and the solution is washed with water, dried and evaporated down. 166.4 g of crude product are obtained, which is recrystallized from methanol. 100 g of the abovementioned compound are obtained as a yellow solid. 1H--NMR (CDCl3 ; δ in ppm): 7.75 (d, 1 H, J=4 Hz, thienyl); 7.3 (d, 1 H, J=4 Hz, thienyl); 4.95 (s, 2 H, CH2 --Br); 4.0 (s, 3 H, O--CH3)

Provenance & Evidence