Réaction #11787

Équation de réaction

2-(5-chloro-2-methoxy-phenylsulfanyl)-2-methyl-propionic acid methyl ester

hydrobromic acid

→

title compound

6-Chloro-3,3-dimethyl-benzo[1,4]oxathiin-2-one

Conditions de réaction

Traitement

1. 1
   TempératureThe reaction was heated
2. 2
   Températureto reflux for 24 hours at which time the solvent
3. 3
   Autrewas removed by evaporation
4. 4
   workup.ADDITIONTo the crude acid phenol was added toluene (5 ml) and catalytic pyridinium p-toluenesulfonate
5. 5
   TempératureAfter 12 hours of heating
6. 6
   Températureat reflux the reaction
7. 7
   Concentrationwas concentrated

Mode opératoire

To 2-(5-chloro-2-methoxy-phenylsulfanyl)-2-methyl-propionic acid methyl ester (prepared from 5-chloro-2-methoxy-benzenesulfonyl chloride: Syn. Comm., (2001), 31, 505–510) (0.25 g, 0.9 mmol) was added 48% hydrobromic acid (5 ml). The reaction was heated to reflux for 24 hours at which time the solvent was removed by evaporation. To the crude acid phenol was added toluene (5 ml) and catalytic pyridinium p-toluenesulfonate. After 12 hours of heating at reflux the reaction was concentrated and the title compound was isolated by chromatography on silica gel (0.27 g).

Source