Water → 5-Oxoheptanoic acid

HRID 258179

Reaktionsgleichung

Reaktionsgleichung von HRID 258179
[CH3:1][CH:2]1[C:7](=[O:8])[CH2:6][CH2:5][CH2:4][C:3]1=[O:9].[OH2:10]>>[O:8]=[C:7]([CH2:2][CH3:1])[CH2:6][CH2:5][CH2:4][C:3]([OH:9])=[O:10]

Komponenten

3

Edukt 2

HCID 962WaterHCID 709452-Methyl-1,3-cyclohexanedione

Produkt 1

HCID 52829795-Oxoheptanoic acid

Reaktionsbedingungen

Temperatur
0 °C

Versuchsvorschrift

A modification of the procedure of Ijima et al. Chem. Pharm. Bull. 19, 1053-5 (1971) was used. A solution of 2-methyl-1,3-cyclohexanedione (40 g, 0.317 mole, Aldrich) and Ba(OH)2.8H2O (360 g) in water (840 mL) was heated at reflux for 48 h. After standing overnight at room temperature and cooling to 0° C., the precipitated barium hydroxide was removed by suction filtration. CO2 gas (generated from Dry Ice) was bubbled through the filtrate to precipitate any remaining barium hydroxide as barium carbonate. The precipitate was removed by suction filtration, and water was removed in vacuum until crystallization started. The resulting mixture was acidified to pH 1 (conc. HCl) and extracted with OEt2 (3×300 mL). The extract was dried (Na2SO4) and stripped of solvent in vacuum giving 5-oxoheptanoic acid (Compound XXI) as a white solid (43.3-45.1 g, 95-99%, lit.112 69%): mp 48°-49.5° C. (lit.182 50° C.); IR (KBr pellet) cm-1 3000 (very br), 1725, 1710, 1690, 1460, 1435, 1420, 1380, 1340, 1280, 1210, 1120, 1085, 985, 910, 770, 685; 1H NMR (200 MHz, CDCl3) δ 10.2 (br, 1H), 2.51 (t, 7.1 Hz, 2H), 2.43 (q, 7.3 Hz, 2H), 2.40 (t, 7.1 Hz, 2H), 1.91 (rough pentet, 2H), 1.06 (t, 7.3 Hz, 3H); 13C NMR (22.5 MHz, CDCl3) δ 211.5, 178.6, 41.0, 36.0, 33.1, 18.7, 7.8; mass spectrum (16 eV) m/e (% base) 144 (M+, 4.1), 126 (61.3), 115 (88.8), 98 (40.0), 87 (40.1), 70 (21.3), 57 (100); TLC (OEt2, I2) Rf=0.37.

Aufarbeitung

  1. temperatureat reflux for 48 h
  2. customthe precipitated barium hydroxide was removed by suction filtration
  3. customCO2 gas (generated from Dry Ice) was bubbled through the filtrate
  4. customto precipitate any remaining barium hydroxide as barium carbonate
  5. customThe precipitate was removed by suction filtration, and water
  6. customwas removed in vacuum until crystallization
  7. extractionextracted with OEt2 (3×300 mL)
  8. dry with materialThe extract was dried (Na2SO4)

Quellen und Nachweise

ORD-Eintrag
ord-596173f4015246309a5bc3a94f23128e
Quelldatensatz
uspto-grants-1993_11
Patentnummer
US05264619

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