1,4-Dibromobutane → Ethyl 1-acetylcyclopentane-1-carboxylate

HRID 1935983Notes

Reaction equation

HRID 1935983 reaction equation
C[O-].[Na+].[C:4]([O:10][CH2:11][CH3:12])(=[O:9])[CH2:5][C:6]([CH3:8])=[O:7].Br[CH2:14][CH2:15][CH2:16][CH2:17]Br>CN(C=O)C>[CH2:11]([O:10][C:4]([C:5]1([C:6](=[O:7])[CH3:8])[CH2:17][CH2:16][CH2:15][CH2:14]1)=[O:9])[CH3:12]

Participants

5

Reactant 3

HCID 80561,4-DibromobutaneHCID 8868Ethyl AcetoacetateHCID 10942334Sodium Methoxide

Product 1

HCID 13050135Ethyl 1-acetylcyclopentane-1-carboxylateYield 78.7%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
90 °C

Procedure

27.2 g (0.4 mol) of sodium methoxide are initially introduced into 300 ml of DMF at approx. 40° C. and stirred. A mixture of 26 g (0.2 mol) of ethyl acetoacetate and 43 g (0.2 mol) of 1,4-dibromobutane is slowly added dropwise to this suspension and the reaction mixture is stirred for approx. 24 hours at this temperature. Towards the end of the reaction, the temperature may optionally be raised to 90° C. for a further hour. The precipitated sodium bromide is filtered out, the DMF removed and the residue fractionated. 29 g (78%) of 1-acetyl-1-cyclopentanecarboxylic acid ethyl ester are obtained. Bp.: 136° C. (1500 Pa); IR: 1745 cm−1 (C═O, ester), 1713 cm−1 (C═O, ketone); MS: m/e=142 (M−42), 114, 101, 96, 86, 67, 43.

Workup

  1. additionis slowly added dropwise to this suspension
  2. stirringthe reaction mixture is stirred for approx. 24 hours at this temperature
  3. customTowards the end of the reaction
  4. filtrationThe precipitated sodium bromide is filtered out
  5. customthe DMF removed

Sources & evidence

ORD record
ord-4a922325092e4776a90a25b6eda0b0b0
Source dataset
uspto-grants-2002_05
Patent number
US06388104B1

Reaction notes

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