Dimethylformamide → 2-(4-Chlorophenyl)-3-(dimethylamino)acrylaldehyde

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Reaction Steps

To a slurry of Vilsmeyer reagent, (formed from a stirred mixture of 92.0 g. of phosphorus oxychloride and 73.0 g. of N,N-dimethylformamide at a temperature below 10° C.) is added 34.12 g. of 4-chlorophenylacetic acid. This mixture is stirred at ambient temperature for 30 minutes, then is heated to 70°-80° C. during which time the mixture becomes effervescent. The mixture is kept at 70°-80° C. for 5.5 hours, then is allowed to cool. The cooled mixture is slowly poured onto cracked ice, and ice is added intermittently to maintain the temperature of the mixture below 15° C. during the portionwise addition of potassium carbonate and until pH 10 is achieved. Then 150 ml. of toluene is added and the mixture is heated on a steam bath for one hour. After cooling, the layers are separated and the aqueous layer is extracted with an additional 100 ml. of toluene. The organic layers are combined, copiously washed with water, dried over anhydrous sodium sulfate and evaporated at reduced pressure to yield a yellow solid. The solid is recrystallized from hexane to give 27.3 g. of the product of the Example as a tan solid, mp. 121°-124° C.

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