Sulfuric Acid → t-Butyl 1-bromocyclopentanecarboxylate

HRID 614441Notes

Reaction equation

HRID 614441 reaction equation
[Br:1][C:2]1([C:7]([OH:9])=[O:8])[CH2:6][CH2:5][CH2:4][CH2:3]1.S(=O)(=O)(O)O.[CH2:15]=[C:16]([CH3:18])[CH3:17]>CCOCC>[Br:1][C:2]1([C:7]([O:9][C:16]([CH3:18])([CH3:17])[CH3:15])=[O:8])[CH2:6][CH2:5][CH2:4][CH2:3]1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 8255IsobutyleneHCID 134118411-Bromocyclopentane-1-carboxylic acid

Product 1

HCID 21329494t-Butyl 1-bromocyclopentanecarboxylateYield 70%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

To a mixture of 1-bromocyclopentanecarboxylic acid (36.99 g) and anhydrous ether (35 ml) in a 500 ml pressure bottle, containing a magnetic stirrer-bar, was added concentrated sulphuric acid (3.5 ml), followed by precondensed isobutene (150 ml). The bottle was sealed, and stirred at ambient temperature for 20 hours. The bottle was then opened excess isobutene was evaporated, and the residue in ether was washed with aqueous sodium bicarbonate solution and water, dried, and concentrated. The residue was distilled under reduced pressure to give the title ester (b.p. 66°-74°/0.5- 2.0 mm) (33.6 g, 70%); λmax (CHBr3) 1702 cm-1 ; τ (CDCl3) 7.78, 8.20 (cyclopentane protons) and 8.54 (C(CH3)3).

Workup

  1. additioncontaining a magnetic stirrer-bar
  2. customThe bottle was sealed
  3. customopened excess isobutene was evaporated
  4. washthe residue in ether was washed with aqueous sodium bicarbonate solution and water
  5. customdried
  6. concentrationconcentrated
  7. distillationThe residue was distilled under reduced pressure

Sources & evidence

ORD record
ord-ee98b627e0cb4cfaa928aaa3fcd79bca
Source dataset
uspto-grants-1979_03
Patent number
US04144393

Reaction notes

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