Water → Pentanoic acid, 2-acetyl-, ethyl ester

HRID 897062Notes

Reaction equation

HRID 897062 reaction equation
C(=O)([O-])[O-].[K+].[K+].[C:7]([O:13][CH2:14][CH3:15])(=[O:12])[CH2:8][C:9]([CH3:11])=[O:10].I[CH2:17][CH2:18][CH3:19].O>O.[Cl-].C([N+](CCCC)(CCCC)CCCC)CCC.C(Cl)(Cl)Cl>[CH2:17]([CH:8]([C:9]([CH3:11])=[O:10])[C:7]([O:13][CH2:14][CH3:15])=[O:12])[CH2:18][CH3:19]

Participants

7

Reactant 4

HCID 962WaterHCID 8868Ethyl AcetoacetateHCID 11430Potassium CarbonateHCID 336431-Iodopropane

Product 1

HCID 95398Pentanoic acid, 2-acetyl-, ethyl ester

Reagents, catalysts & solvents 2

HCID 16212273Tetrabutylammonium chloride hydrateCatalystHCID 6212ChloroformSolvent

Procedure

Keto ester 9 was synthesized according to the method of Barbry et. al. [71]. A mixture of potassium carbonate (14 g, 0.10 mol), ethyl acetoacetate (4.3 g, 33 mmol), 1-iodopropane (5.7 g, 33.7 mmol), tetrabutylammonium chloride hydrate (10 g), water (50 mL) and chloroform (50 mL) was stirred at room temperature for 40 h. The aqueous layer was then separated, acidified with 5M hydrochloric acid and extracted with ether. The organic portions were combined, concentrated and the residual tetrabutylammonium chloride was precipitated by addition of ether. After filtration, the ethereal filtrate was dried (MgSO4) and evaporated to give a yellow liquid which was fractionated by distillation. The fraction which boiled at 93° C. at ˜15 mmHg (Lit. [72] 106-107° C., 22 mmHg) was collected (2.13 g) and 1H NMR has indicated that this colourless liquid contained about 5% of ethyl acetoacetate and 95% of 9; δH (270 MHz, CDCl3) 0.93 (3H, t, J=7.3 Hz, CH3), 1.28 (5H, m, —CH2CH2CH3 and CH3), 1.83 (2H, m, —CH2CH2CH3), 2.23 (3H, s, CH3CO), 3.42 (1H, t, J=7.3 Hz, —CH) and 4.20 (2H, q, J=7.3 Hz, COOCH2CH3); MS (EI) m/z (rel. intensity) 172.1(25, M+), 143.1[50, (M-Et)+], 130.1[28, (M+H—CH3CO)+], 115.1(23), 101.1(40), 85.0(20), 69.0(30), 55.0(30), 43.0[100, (CH3CO)+]. This crude was used for the next reaction without further purification.

Workup

  1. customThe aqueous layer was then separated
  2. extractionextracted with ether
  3. concentrationconcentrated
  4. customthe residual tetrabutylammonium chloride was precipitated by addition of ether
  5. filtrationAfter filtration
  6. dry with materialthe ethereal filtrate was dried (MgSO4)
  7. customevaporated
  8. customto give a yellow liquid which
  9. distillationwas fractionated by distillation
  10. customThe fraction which boiled at 93° C. at ˜15 mmHg (Lit. [72] 106-107° C., 22 mmHg) was collected (2.13 g) and 1H NMR
  11. customThis crude was used for the next reaction without further purification

Sources & evidence

ORD record
ord-85dfd8b11f1f4743852fdd47bdc7858a
Source dataset
uspto-grants-2005_07
Patent number
US06921776B1

Reaction notes

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