Hydrochloric Acid → Methyl 1-[2-(4-bromophenyl)-2-oxoethyl]cyclopentanecarboxylate

HRID 30843

Reaction equation

HRID 30843 reaction equation
Cl[C:2](=[O:13])[CH2:3][C:4]1([C:9]([O:11][CH3:12])=[O:10])[CH2:8][CH2:7][CH2:6][CH2:5]1.[Br:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1.[Cl-].[Cl-].[Cl-].[Al+3].Cl>C(OCC)(=O)C.O.ClCCl>[Br:14][C:15]1[CH:20]=[CH:19][C:18]([C:2](=[O:13])[CH2:3][C:4]2([C:9]([O:11][CH3:12])=[O:10])[CH2:8][CH2:7][CH2:6][CH2:5]2)=[CH:17][CH:16]=1

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 7961BromobenzeneHCID 6451240Aluminum(III) ChlorideHCID 21985709Methyl 1-(2-chloro-2-oxoethyl)cyclopentanecarboxylate

Product 1

HCID 21985683Methyl 1-[2-(4-bromophenyl)-2-oxoethyl]cyclopentanecarboxylate

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6344DichloromethaneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
0 °C

Procedure

To a 150 mL flask was added dichloromethane (70 mL), methyl 1-(2-chloro-2-oxoethyl)cyclopentanecarboxylate] (3.50 g, 16.8 mmol) [prepared as described by Bajaj, et al., J. Indian Chem. Soc. 52:1076-78, 1975] and bromobenzene (2.77 g, 17.6 mmol), and the reaction mixture cooled to 0° C. before aluminum trichloride (4.77 g, 35.7 mmol) was slowly added. The mixture was stirred for 1 h at 0° C., then for 12 h at rt. The reaction mixture was slowly poured into 50 mL chilled (0° C.) 1 N aqueous hydrochloric acid solution. Water (50 mL) was added, followed by ethyl acetate (100 mL), and the mixture stirred for 30 minutes. The layers were separated and the aqueous layer extracted with additional ethyl acetate (100 mL). The combined organic layer was washed with saturated aqueous sodium chloride (100 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to yield a brown oil which was purified by flash chromatography (10:1/hexane:ethyl acetate) to afford methyl 1-[2-(4-bromophenyl)-2-oxoethyl]cyclopentane carboxylate as a yellow, crystalline solid (1.62 g, 30%). LC-MS ret. time 3.45 min, m/z 324.8 (MH+); 1H NMR (300 MHz, CDCl3) δ 1.50-1.83 (overlapping signals, 6H), 2.22-2.33 (m, 2H), 3.37 (s, 2H), 3.66 (s, 3H), 7.59 (d, 2H), 7.80 (d, 2H).

Workup

  1. additionwas slowly added
  2. waitfor 12 h at rt
  3. additionThe reaction mixture was slowly poured into 50 mL
  4. stirringthe mixture stirred for 30 minutes
  5. customThe layers were separated
  6. extractionthe aqueous layer extracted with additional ethyl acetate (100 mL)
  7. washThe combined organic layer was washed with saturated aqueous sodium chloride (100 mL)
  8. dry with materialdried over anhydrous sodium sulfate
  9. concentrationconcentrated under reduced pressure
  10. customto yield a brown oil which
  11. customwas purified by flash chromatography (10:1/hexane:ethyl acetate)

Sources & evidence

ORD record
ord-219b011c139240ab83ed47388a8fc807
Source dataset
uspto-grants-2008_09
Patent number
US07423156B2

Linked notes

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