Sulfuric Acid → t-Butyl 1-bromocyclopentanecarboxylate

HRID 839455Notes

Reaction equation

HRID 839455 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 (36.99g) and anhydrous ether (35ml) in a 500ml pressure bottle, containing a magnetic stirrer-bar, was added concentrated sulphuric acid (3.5ml), followed by precondensed isobutene (150ml). 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°/0.5-2.0mm) (33.6g, 70%); λmax (CHBr3) 1702cm-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. customexcess 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-cb5dec0f964f47bf9d9619ca7b9227c7
Source dataset
uspto-grants-1978_06
Patent number
US04095021

Reaction notes

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