反应详情

The starting material is prepared as follows: The mixture of 4-(4-acetamidophenylamino)-3-amino-5-(2-acetamidophenylsulfamoyl)-benzoic acid, 60 ml of diethyleneglycol diethyl ether and 30 ml of furfural is heated to 110° for 4 hours and evaporated under reduced pressure. The residue is taken up in 100 ml of anhydrous ethanol, the solution cooled with an ice bath and 4.5 g of sodium borohydride are added portionwise while stiring. After one hour the ice bath is removed and the mixture stirred overnight at room temperature. Thereupon 2.25 g of sodium borohydride are added, the mixture stirred for 90 minutes and diluted with 150 ml of water. It is filtered, the filtrate concentrated and the concentrate strongly acidified with hydrochloric acid. The precipitate formed is collected and recrystallized twice from 50% aqueous ethanol, to yield the 4-(4-acetamidophenylamino)-3-furfurylamino-5-(2-acetamidophenylsulfamoyl)-benzoic acid melting at 258° with decomposition. [Analogously the 5-(4-acetamidophenylsulfamoyl)-isomer is prepared m.p. 266° (dec.)].

1. customThe starting material is prepared
2. temperatureis heated to 110° for 4 hours
3. customevaporated under reduced pressure
4. temperaturethe solution cooled with an ice bath
5. addition4.5 g of sodium borohydride are added portionwise
6. customAfter one hour the ice bath is removed
7. additionThereupon 2.25 g of sodium borohydride are added
8. stirringthe mixture stirred for 90 minutes
9. additiondiluted with 150 ml of water
10. filtrationIt is filtered
11. concentrationthe filtrate concentrated
12. concentrationthe concentrate strongly
13. customThe precipitate formed
14. customis collected
15. customrecrystallized twice from 50% aqueous ethanol