Reaktion #459419

Reaktionsgleichung

chlorosulfonic acid

dimethylamine

hydrochloric acid

2-bromobenzoic acid

→

2-bromo-5-dimethylaminosulfonylbenzoic acid

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeat 0°-5° C.
2. 2
   workup.STIRRINGThe mixture was stirred
3. 3
   Temperaturrefluxed for three hours
4. 4
   Temperaturit was cooled
5. 5
   FiltrationThe solid was filtered
6. 6
   Waschenwashed with cold water until the filtrate
7. 7
   SonstigeThe solid, thus isolated
8. 8
   workup.ADDITIONwas added, in portions, to 200 ml
9. 9
   workup.ADDITIONAfter being diluted with 500 ml
10. 10
    SonstigeRecrystallization of the precipitated solid from aqueous ethanol

Vorschrift

To 160 ml. of chlorosulfonic acid stirring at 0°-5° C. was gradually added 100.5 g. (0.33 mole) of 2-bromobenzoic acid. Stirring was continued as the temperature was allowed to increase to 25° C. The mixture was stirred and refluxed for three hours, then it was cooled and poured into ice-water. The solid was filtered and then washed with cold water until the filtrate was no longer acidic. The solid, thus isolated, was added, in portions, to 200 ml. of a 40% aqueous solution of dimethylamine. After being diluted with 500 ml. of water, the solution was made acidic with 2.5 N hydrochloric acid. Recrystallization of the precipitated solid from aqueous ethanol gave crystals of 2-bromo-5-dimethylaminosulfonylbenzoic acid, m.p. 170°-172° C.

Quelle