Réaction #67411

Équation de réaction

Water

1-(4-methoxy-3-nitro-phenyl)-cyclopropane-carboxylic acid methyl ester

BBr3

→

1-(4-hydroxy-3-nitro-phenyl)-cyclopropanecarboxylic acid methyl ester

Rendement 87.9%

Solvants

CH2Cl2

Conditions de réaction

Traitement

1. 1
   Températureto warm to −30° C.
2. 2
   workup.STIRRINGstirred at this temperature for 3 hours
3. 3
   Températureto warm room temperature before it
4. 4
   Extractionwas extracted with EtOAc (200 mL×3)
5. 5
   SéchageThe combined organic layers were dried over anhydrous Na2SO4
6. 6
   Autreevaporated under vacuum
7. 7
   Autreto give the crude product, which
8. 8
   Autrewas purified by column chromatography on silica gel (petroleum ether/EtOAc 15:1)

Mode opératoire

To a solution of 1-(4-methoxy-3-nitro-phenyl)-cyclopropane-carboxylic acid methyl ester (10.0 g, 39.8 mmol) in CH2Cl2 (100 mL) was added BBr3 (12.0 g, 47.8 mmol) at −70° C. The mixture was stirred at −70° C. for 1 hour, then allowed to warm to −30° C. and stirred at this temperature for 3 hours. Water (50 mL) was added dropwise at −20° C., and the resulting mixture was allowed to warm room temperature before it was extracted with EtOAc (200 mL×3). The combined organic layers were dried over anhydrous Na2SO4 and evaporated under vacuum to give the crude product, which was purified by column chromatography on silica gel (petroleum ether/EtOAc 15:1) to afford 1-(4-hydroxy-3-nitro-phenyl)-cyclopropanecarboxylic acid methyl ester (8.3 g, 78%). 1H NMR (CDCl3, 400 MHz) δ 10.5 (s, 1H), 8.05 (d, J=2.4 Hz, 1H), 7.59 (dd, J=2.0, 8.8 Hz, 1H), 7.11 (d, J=8.4 Hz, 1H), 3.64 (s, 3H), 1.68-1.64 (m, 2H), 1.20-1.15 (m, 2H).

Source