반응 #76437

반응 방정식

Boron tribromide

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

→

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

수율 99.4%

용매

dichloromethane

반응 조건

후처리

1. 1
   workup.ADDITIONOnce the addition
2. 2
   기타was removed
3. 3
   온도The mixture was cooled to 0° C.
4. 4
   workup.ADDITIONexcess methanol added cautiously
5. 5
   기타The solvent was evaporated in vacuo
6. 6
   기타the residue was partitioned between ethyl acetate and brine
7. 7
   건조The organic layer was dried over anhydrous magnesium sulfate
8. 8
   여과filtered
9. 9
   기타the filtrate was evaporated in vacuo

실험 절차

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.

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