Benzyl Alcohol → Dibenzyl 2,4-dibromoglutarate

HRID 981030Notes

Reaction equation

HRID 981030 reaction equation
[Br:1][CH:2]1[CH2:8][CH:7]([Br:9])[C:6](=[O:10])[O:5][C:3]1=[O:4].[CH2:11]([OH:18])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1>O.C1(C)C=CC(S(O)(=O)=O)=CC=1.C1C=CC=CC=1>[Br:9][CH:7]([CH2:8][CH:2]([Br:1])[C:3]([O:5][CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:4])[C:6]([O:18][CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:10]

Participants

5

Reactant 2

HCID 244Benzyl AlcoholHCID 14654375HCID 14654375, compound

Product 1

HCID 14654378Dibenzyl 2,4-dibromoglutarateYield 100.2%

Reagents, catalysts & solvents 2

HCID 521998p-Toluenesulfonic acid monohydrateCatalystHCID 241BenzeneSolvent2×

Procedure

2.18 g (8 mmol) of 2,4-dibromoglutaric anhydride, 2.1 ml (20 mmol) of benzyl alcohol, and 2 ml of benzene are stirred for 1.5 hours at room temperature. 76 mg (0.4 mmol) of p-toluenesulfonic acid monohydrate and 8 ml of benzene are added, and the solution is refluxed under a Dean-Stark trap for 2 hours. Filtration over silica gel and evaporation yields 3.77 g (100%) of dibenzyl 2,4-dibromoglutarate as a colourless oil. 1H NMR (CDl3): δ7.37 (br. s., 10H), 5.21 (narrow AB system, 4H, J=12.5); dl isomer: δ4.55 (dd, 2H, J=6.5, 7.5), 2.69 (dd, 2H, J=6.5, 7.5); meso isomer: δ4.42 (t, 2H, J=7.5), 2.90 (dt, 1H, J=7.5 (t), 14.5 (d)), 2.66 (dt, 1H, J=7.5 (t), 14.5 (d)); dl/meso=6:1. IR (neat): 3034, 1740, 1499, 1456, 1385, 1273, 1154, 750, 696 cm-1.

Workup

  1. temperaturethe solution is refluxed under a Dean-Stark trap for 2 hours
  2. filtrationFiltration
  3. customover silica gel and evaporation

Sources & evidence

ORD record
ord-6c71984722aa438c9634ee24afef03da
Source dataset
uspto-grants-1991_02
Patent number
US04990504

Reaction notes

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