Bromine → Methyl 4-(3-bromo-4-oxobutyl)benzoate

HRID 36766Notes

Reaction equation

HRID 36766 reaction equation
C[Si](C)(C)[O:3][CH:4]=[CH:5][CH2:6][CH2:7][C:8]1[CH:17]=[CH:16][C:11]([C:12]([O:14][CH3:15])=[O:13])=[CH:10][CH:9]=1.[Br:20]Br>C(Cl)(Cl)(Cl)Cl>[Br:20][CH:5]([CH2:6][CH2:7][C:8]1[CH:17]=[CH:16][C:11]([C:12]([O:14][CH3:15])=[O:13])=[CH:10][CH:9]=1)[CH:4]=[O:3]

Participants

4

Reactant 2

HCID 24408BromineHCID 54025504Methyl 4-(4-trimethylsilyloxy-3-butenyl)benzoate

Product 1

HCID 15284221Methyl 4-(3-bromo-4-oxobutyl)benzoateYield 100.8%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent2×

Procedure

To 4.46 g (16 mmol) of methyl 4-(4-trimethylsilyloxy-3 -butenyl)benzoate, prepared in Preparation 1, in 16 ml carbon tetrachloride at -20° C. was slowly added 2.56 g (16 mmol) of bromine in 16 ml carbon tetrachloride over 4 hours. The mixture was allowed to come to room temperature then decanted from a small amount of insoluble material. The solvent was removed by vacuum rotary evaporation to give 4.60 g of 2-bromo-4-(4-carbomethoxyphenyl)butanal. Chromatography purification (silica; hexane-ethyl acetate 7:3) of the above product gave 4.0 g in a yield of 87.8 percent. 1H NMR (CDCl3) δ2.24 (m, 1H), 2,36 (m, 1H), 2.81 (m, 1H), 2.90 (m, 1H), 3.90 (s, 3H), 4.16 (m, 1H), 7.27 (d, J=8.2 Hz, 2H), 7.97 (d, J=8.2 Hz, 2H), 9.46 (d, J=2.1 Hz, 1H); 13C NMR (CDCl3) δ32.5, 32.7, 51.7, 54.3, 128.3, 128.4, 129.8, 145.0, 166.6, 192.0.

Workup

  1. customover 4 hours
  2. customto come to room temperature
  3. customthen decanted from a small amount of insoluble material
  4. customThe solvent was removed by vacuum rotary evaporation

Sources & evidence

ORD record
ord-fd2ace01a4a04a1d9db3fa1806db934e
Source dataset
uspto-grants-1995_05
Patent number
US05416211

Reaction notes

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