反应详情

An additional study was made in accordance with FIG. 2, utilizing aqueous phthalic acid solutions having about 28% by weight of phthalic acid. The toluene phase having about 10% by weight of triethylamine obtained from the extraction column was extracted with a 35% by weight phthalic acid solution having up to about 25% by weight of triethylamine. It was found that about 85-95% by weight of the triethylamine was removed from the toluene phase. The extracted toluene was further processed by feeding it to a thin film evaporator. Toluene was obtained substantially free of triethylamine which was recycled to the extraction column, while the bottom of the thin film evaporator was further processed to provide aromatic bis(ether phthalimide) and phthalimide.

1. customobtained from the extraction column
2. extractionwas extracted with a 35% by weight phthalic acid solution
3. customwas removed from the toluene phase
4. customto a thin film evaporator
5. customToluene was obtained substantially free of triethylamine which
6. extractionwas recycled to the extraction column
7. customwhile the bottom of the thin film evaporator