반응 #76275

반응 방정식

3-bromobenzyl methyl ether

lithium diisopropylamide

ethyl isobutyrate

DMPU

3,3′-bis(bromomethyl)benzophenone

→

3-{3-[3-(2-ethoxycarbonyl-2-methyl-propyl)-benzoyl]-phenyl}-2,2-dimethyl -prop ionic acid ethyl ester

수율 90.0%

용매

THF

반응 조건

후처리

1. 1
   기타prepared
2. 2
   온도to warm to rt
3. 3
   workup.STIRRINGstirred for 30 min
4. 4
   기타The THF was removed under reduced pressure
5. 5
   workup.ADDITIONthe residue was diluted with saturated NH4Cl (280 mL)
6. 6
   추출The aqueous layer was extracted with ethyl acetate (3×100 mL)
7. 7
   세척The combined organic layers were washed with brine (200 mL), 5% HCl (100 mL), and saturated NaHCO3 solution (50 mL)
8. 8
   건조dried over anhydrous Na2SO4
9. 9
   농축concentrated in vacuo

실험 절차

A solution of lithium diisopropylamide (LDA, 2.0 M in heptane/THF, ethyl benzene, 42.2 mL, 84.4 mmol) was added drop-wise to a solution of ethyl isobutyrate (9.78 g, 84.3 mmol) in anhydrous THF (30 mL) at −78° C. The mixture was allowed to stir at −78° C. for 1 h, before 3,3′-bis(bromomethyl)benzophenone ((prepared according to Shultz, D. A.; Fox, M. A. J. Am. Chem. Soc. 1989, 16, 6311, from 3-bromobenzyl methyl ether (Friedman, L.; Shechter, H. J. Org. Chem. 1961, 26, 2522), 10.34 g, 28.1 mmol) was added, followed by addition of DMPU (2.7 g, 17 mmol). The mixture was stirred for 30 min at −78° C., allowed to warm to rt, and stirred for 30 min. The THF was removed under reduced pressure and the residue was diluted with saturated NH4Cl (280 mL). The aqueous layer was extracted with ethyl acetate (3×100 mL). The combined organic layers were washed with brine (200 mL), 5% HCl (100 mL), and saturated NaHCO3 solution (50 mL), then dried over anhydrous Na2SO4 and concentrated in vacuo to furnish 3-{3-[3-(2-ethoxycarbonyl-2-methyl-propyl)-benzoyl]-phenyl}-2,2-dimethyl -prop ionic acid ethyl ester (11.0 g, 90%) as an oil. 1H NMR (300 MHz, CDCl3): δ (ppm): 7.8-7.2 (m, 8H), 3.98 (q, J=6.9 Hz, 4H), 2.83 (s, 4H), 1.2-0.8 (m, 18H). 13C NMR (75 MHz, CDCl3): δ (ppm): 196.5, 176.8, 138.1, 137.2, 134.0, 131.4, 128.1, 127.7, 60.3, 45.7, 43.3, 24.8, 13.9.

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