Reaktion #76437

Reaktionsgleichung

Boron tribromide

N-(4-chloro-3-methylisothiazol-5-yl)-2-(4-methoxyphenyl)propionamide

→

N-(4-chloro-3-methylisothiazol-5-yl)-2-(4-hydroxyphenyl)propionamide

Ausbeute 99.4%

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONOnce the addition
2. 2
   Sonstigewas removed
3. 3
   TemperaturThe mixture was cooled to 0° C.
4. 4
   workup.ADDITIONexcess methanol added cautiously
5. 5
   SonstigeThe solvent was evaporated in vacuo
6. 6
   Sonstigethe residue was partitioned between ethyl acetate and brine
7. 7
   TrocknenThe organic layer was dried over anhydrous magnesium sulfate
8. 8
   Filtrationfiltered
9. 9
   Sonstigethe filtrate was evaporated in vacuo

Vorschrift

Boron tribromide (1.0 M solution in dichloromethane, 110 ml, 0.11 mol) was added dropwise to a stirred solution of N-(4-chloro-3-methylisothiazol-5-yl)-2-(4-methoxyphenyl)propionamide (125 g, 0.040 mol) in dichloromethane (200 ml) at −70° C. Once the addition was complete the cooling bath was removed and the mixture was allowed to warm to room temperature overnight. The mixture was cooled to 0° C. and excess methanol added cautiously. The solvent was evaporated in vacuo, and the residue was partitioned between ethyl acetate and brine. The organic layer was dried over anhydrous magnesium sulfate, filtered and the filtrate was evaporated in vacuo to give N-(4-chloro-3-methylisothiazol-5-yl)-2-(4-hydroxyphenyl)propionamide (11.8 g), which was used without further purification in the next step.

Quelle