反应详情

2.59 g (0.01 mole) of 4-(3,5-dichloro-4-methylphenyl)-4-oxo-2-butenoic acid, prepared as described in step (b) above, were suspended in 10 ml of water, and then 3.5 g (0.01 mole) of a 20% w/v aqueous solution of sodium methanethiolate were poured into the suspension, whilst water-cooling and stirring. The mixture was then stirred for a further 30 minutes, after which 2 ml of concentrated hydrochloric acid were added dropwise to the mixture, whilst water-cooling, and the resulting crystals were collected by filtration, washed with water and air-dried, to give 3.03 g (yield 98.7%) of the desired 4-(3,5-dichloro-4-methylphenyl)-2-methylthio-4-oxobutyric acid, melting at 158°-160° C.

1. temperaturecooling
2. stirringThe mixture was then stirred for a further 30 minutes
3. temperaturecooling
4. filtrationthe resulting crystals were collected by filtration
5. washwashed with water
6. customair-dried