Reaction #531874

Reaction equation

N-(3,5-Dichloro-2-hydroxybenzoyl)benzotriazole

cyclopropylmagnesium bromide

→

ketone

cyclopropyl-(3,5-dichloro-2-hydroxyphenyl)-methanone

Solvents

THF

Conditions

Workup

1. 1
   Otheraccording to Katritizky et al., Synthesis 2007, 20, 3141-3146, which
2. 2
   OtherThe cooling bath was removed
3. 3
   Temperatureto warm to 25° C.
4. 4
   workup.STIRRINGstir for 3 h
5. 5
   OtherThe reaction was quenched by addition of 10 mL
6. 6
   workup.STIRRINGshaken with EtOAc (50 mL) plus 20% citric acid solution (30 mL)
7. 7
   WashThe organic phase was washed with satd NaCl (20 mL)
8. 8
   Dryingdried (Na2SO4)
9. 9
   Otherevaporated
10. 10
    OtherThe residue was purified by silica gel chromatography with 0-20% EtOAc/hexane

Procedure

N-(3,5-Dichloro-2-hydroxybenzoyl)benzotriazole (prepared according to Katritizky et al., Synthesis 2007, 20, 3141-3146, which is expressly incorporated by reference herein; 2.0 g, 6.5 mmol) was stirred in dry THF (25 mL), cooled to −30° C., treated in portions with cyclopropylmagnesium bromide (0.5 M in THF; 28 mL, 14 mmol) and stirred at −30° C. for 30 min. The cooling bath was removed and the mixture was allowed to warm to 25° C. and stir for 3 h. The reaction was quenched by addition of 10 mL satd NH4Cl, and shaken with EtOAc (50 mL) plus 20% citric acid solution (30 mL). The organic phase was washed with satd NaCl (20 mL), dried (Na2SO4) and evaporated. The residue was purified by silica gel chromatography with 0-20% EtOAc/hexane to give the purified ketone (450 mg): 1H NMR (400 MHz, CDCl3) δ 13.03 (s, 1H), 7.87 (d, J=2.5 Hz, 1H), 7.57 (d, J=2.5 Hz, 1H), 2.70-2.54 (m, 1H), 1.41-1.32 (m, 2H), 1.24-1.15 (m, 2H); EIMS m/z 230.

Source