反应详情

30.2 g of ethyl 3-dimethylaminoacrylate and 29.3 ml of triethylamine were dissolved in 180 ml of toluene and heated to reflux. At this temperature there was added dropwise thereto a solution of 53 g of 4-bromo-2-chloro-benzoyl chloride in 50 ml of toluene over 30 min. and the mixture was subsequently stirred at reflux for a further 1 hr. The mixture was left to cool to room temperature and was stirred in an ice bath for a further 30 min. The suspension was filtered and the triethylamine hydrochloride was washed with 40 ml of ice-cold toluene. The filtrate was concentrated to half of the volume and then, for crystallization, diluted with 100 ml of hexane and stirred in an ice bath for a further 1 hr. 51.2 g (67%) of ethyl 2-(4-bromo-2-chlorobenzoyl)-3-dimethylamino-acrylate were obtained as white crystals. M.p. 101°.

1. temperatureheated to reflux
2. additionAt this temperature there was added dropwise
3. temperatureat reflux for a further 1 hr
4. waitThe mixture was left
5. stirringwas stirred in an ice bath for a further 30 min
6. filtrationThe suspension was filtered
7. washthe triethylamine hydrochloride was washed with 40 ml of ice-cold toluene
8. concentrationThe filtrate was concentrated to half of the volume
9. customfor crystallization
10. additiondiluted with 100 ml of hexane
11. stirringstirred in an ice bath for a further 1 hr