Reaktion #216223

Reaktionsgleichung

sodium bicarbonate

4-isopropyl-6-methoxysaccharin

boron tribromide

→

6-hydroxy-4-isopropylsaccharin

Ausbeute 96.0%

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONWhen addition
2. 2
   Temperaturwas heated
3. 3
   Temperaturunder reflux for about five hours
4. 4
   Temperaturcooled
5. 5
   ExtraktionThe aqueous solution was extracted once with ethyl acetate
6. 6
   ExtraktionExtraction of the mixture with ethyl acetate/diethyl ether (8:2)
7. 7
   Sonstigedrying
8. 8
   Sonstigethe organic extracts and removal of the solvent in vacuo

Vorschrift

To a solution of 1.0 g (0.0039 mol) of 4-isopropyl-6-methoxysaccharin in 15 ml of MDC was added at ambient temperature 1.28 g (5.12 ml) of a 1M solution of boron tribromide in MDC. When addition was complete the reaction mixture was heated under reflux for about five hours, cooled, taken to dryness in vacuo and the residue treated with ice and saturated sodium bicarbonate. The aqueous solution was extracted once with ethyl acetate and then acidified to pH 1 with concentrated hydrochloric acid. Extraction of the mixture with ethyl acetate/diethyl ether (8:2), drying the organic extracts and removal of the solvent in vacuo afforded 0.9 g (96%) of 6-hydroxy-4-isopropylsaccharin as a white crystalline solid which was used as such in the next step.

Quelle