Reaktion #46114

Reaktionsgleichung

4,5-dichloro-2-cyclopropylaminobenzenesulphonamide

ethyl orthoformate

→

6,7-dichloro-4-cyclopropyl-4H-1,2,4-benzothiadiazine 1,1-dioxide

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe suspension obtained
2. 2
   Temperaturis cooled on an ice bath
3. 3
   Filtrationthe insoluble material is collected by filtration
4. 4
   Waschenwashed with ether
5. 5
   Sonstigedried
6. 6
   workup.DISSOLUTIONThe solid is re-dissolved in a mixture of acetone and methanol in the hot state
7. 7
   workup.ADDITIONthe hot solution is treated with absorbent carbon
8. 8
   Filtrationfiltered
9. 9
   Einengenconcentrated to dryness
10. 10
    SonstigeThe residue is recrystallised from methanol

Vorschrift

In a round-bottom flask, a mixture of 4,5-dichloro-2-cyclopropylaminobenzenesulphonamide from the Step above (2.5 g) and ethyl orthoformate (25 mL) is heated in the open state at 150° C. for 1 hour. The suspension obtained is cooled on an ice bath, and the insoluble material is collected by filtration, washed with ether and dried. The solid is re-dissolved in a mixture of acetone and methanol in the hot state and the hot solution is treated with absorbent carbon and then filtered and concentrated to dryness. The residue is recrystallised from methanol.

Quelle