反应详情

A mixture of 4-(3-benzyloxyphenylthio)-2-chlorobenzaldehyde (1) and ethyl diethylphosphonoacetate (2) is stirred for 3 to 8 hours at 50 to 80° C. in an organic solvent, such as dimethylformamide or dimethylsulfoxide, in the presence of a base, such as potassium bicarbonate, sodium bicarbonate, potassium carbonate or sodium carbonate. Subsequently, the reaction mixture is chilled in an ice water bath while being stirred and water is added. The resulting crystals are collected by filtration and washed with aqueous 2-propanol to give ethyl 3-[4-(3-benzyloxyphenylthio)-2-chlorophenyl]acrylate (3) as crude crystals. This product is dissolved in ethylacetate and the mixture was washed with water. The organic layer is concentrated under reduced pressure to obtain a pale yellow oil. To this product, acetone is added and the mixture is stirred while being chilled to form crystals (Crystal seeds are added when necessary). Water is then added and the mixture is stirred while being chilled. The resulting crystals are collected by filtration and washed with acetone-water. The crystals are then dried at 40° C. or below to give ethyl 3-[4-(3-benzyloxyphenylthio)-2-chlorophenyl]acrylate (3) or a hydrate thereof.

1. temperatureSubsequently, the reaction mixture is chilled in an ice water bath
2. filtrationThe resulting crystals are collected by filtration
3. washwashed with aqueous 2-propanol