反应详情

126 Grams of 6-chloro-4-fluoro-3-sulfamoylbenzoic acid (0.5 mole) were stirred with 0.2 l of N-butylpiperazine for 2 hours at 110° C. Subsequently the reaction solution was poured into 2 l of water, a small amount of amorphous precipitate formed was separated, and the filtrate was adjusted to a pH of 7.5 with 2N HCl. After having stood overnight at room temperature, the crystalline precipitate was suction-filtered and was recrystallized from a mixture of ethanol and water.

1. customa small amount of amorphous precipitate formed
2. customwas separated
3. filtrationthe crystalline precipitate was suction-filtered
4. customwas recrystallized from a mixture of ethanol and water