反应详情

A mixture of 0.5 g of 4-(2-fluoro-5-trifluoromethyl-phenyl)-thiazol-2-ylamine hydrobromide with 0.38 g of 4-acetaminobenzenesulfonyl chloride was stirred for 2 hours with 2 ml of pyridine. The resulting, red colored suspension was poured into 30 ml of 1N hydrochloric acid and stirred at room temperature for 30 minutes. The separated solid was dissolved in a mixture of 20 ml of ethanol and 20 ml of 2N sodium hydroxide solution. After the addition of 0.5 g of active charcoal the mixture was stirred at room temperature for 30 minutes and subsequently the active charcoal was filtered off. The 4-acetamino-N-[4-(2-fluoro-5-trifluoromethyl-phenyl)-thiazol-2-yl]-benzenesulfonamide, which separated upon neutralization with concentrated hydrochloric acid, was suspended in 9 ml of 6N hydrochloric acid and boiled for 36 hours. The mixture was cooled, treated with 30 ml of ethanol and neutralized with 2N sodium hydroxide solution. Recrystallization of the product, which thereby separated, from 20 ml of 50% ethanol yielded 0.21 g of 4-amino-N-[4-(2-fluoro-5-trifluoromethyl-phenyl)-thiazol-2-yl]benzenesulfonamide as colorless crystals.

1. stirringwas stirred at room temperature for 30 minutes
2. filtrationsubsequently the active charcoal was filtered off
3. customThe 4-acetamino-N-[4-(2-fluoro-5-trifluoromethyl-phenyl)-thiazol-2-yl]-benzenesulfonamide, which separated upon neutralization with concentrated hydrochloric acid
4. waitboiled for 36 hours
5. temperatureThe mixture was cooled
6. additiontreated with 30 ml of ethanol and neutralized with 2N sodium hydroxide solution
7. customRecrystallization of the product, which
8. customthereby separated, from 20 ml of 50% ethanol