3-Chloropropionyl chloride → 3-chloro-N-[2-chloro-4-formyl-5-(methyloxy)phenyl]propanamide

Participants

Reaction Conditions

Reaction Steps

3-Chloropropionyl chloride (98.4 ml, 1.0 mol) was added over 30 minutes to a stirred suspension of 4-amino-5-chloro-2-methoxybenzaldehyde (47.4 g, 0.26 mol) ensuring the reaction temperature did not exceed 20° C. After the addition was complete the reaction was stirred at 20° C. for a further 2 hours and then filtered. The filtrate was concentrated to 150 ml under reduced pressure and then diluted with ethyl acetate (100 ml) and water (400 ml). The mixture was stirred at 20° C. for 1 hour and then filtered to give 3-chloro-N-[2-chloro-4-formyl-5-(methyloxy)phenyl]propanamide as an off-white solid which was not isolated but suspended in tetrahydrofuran (730 ml) and treated with diisopropylethylamine (154 ml, 0.88 mol). The resulting mixture was stirred at 45° C. for 46 hours and then concentrated under reduced pressure to leave a residue which was diluted with ethyl acetate (300 ml), washed with 2M hydrochloric acid (4×100 ml) and concentrated under reduced pressure to give N-[2-chloro-4-formyl-5-(methyloxy)phenyl]-2-propenamide (37.8 g, 62%).

Provenance & Evidence