Dimethyl Carbonate → 2-Carbomethoxy-3-tropanone

HRID 1937428Notes

Reaction equation

HRID 1937428 reaction equation
[H-].[Na+].CO[C:5](=[O:8])[O:6][CH3:7].[C@@H:9]12[N:16]([CH3:17])[C@@H:13]([CH2:14][CH2:15]1)[CH2:12][C:11](=[O:18])[CH2:10]2.[H][H].[Cl-].[NH4+]>C1CCCCC1.O.CO>[C:5]([CH:12]1[C:11](=[O:18])[CH2:10][C@H:9]2[N:16]([CH3:17])[C@@H:13]1[CH2:14][CH2:15]2)([O:6][CH3:7])=[O:8]

Participants

9

Reactant 5

HCID 12021Dimethyl CarbonateHCID 24758Sodium hydrideHCID 25517Ammonium ChlorideHCID 446337TropinoneHCID 178418361HCID 178418361, compound

Product 1

HCID 110955802-Carbomethoxy-3-tropanone

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolvent2×HCID 8078CyclohexaneSolvent2×

Procedure

To a suspension of sodium hydride (3.2 g 80%, 107 mmol, prewashed in cyclohexane) and dimethylcarbonate (9.13 ml, 108 mmol) in absolute cyclohexane heated to reflux temperature, a solution of (+−)-3-tropanone (6.9 g, 50 mmol) in 50 ml absolute cyclohexane was added over 15 minutes. No hydrogen evolution was apparent so 0.2 ml methanol was added. The reaction mixture was stirred over night at reflux temperature and after cooling to ambient temperature 75 ml water was carefully added. To the water phase was added 40 g ammonium chloride and the resulting mixture was extracted 8 times with methylene chloride. The combined methylene chloride organic phases were dried and concentrated in vacuo followed by column chromatography of the crude product using methylene chloride with increasing amounts (up to 10%) of methanol as eluent. The fractions containing the product were concentrated in vacuo and the resulting oil was subjected to Kugelrohr destillation (1 mbar, 120° C., yielding the title compound as orange crystals, m.p. 104-107° C.

Workup

  1. temperatureheated
  2. temperatureto reflux temperature
  3. additionwas added
  4. temperatureat reflux temperature
  5. additionwas carefully added
  6. extractionthe resulting mixture was extracted 8 times with methylene chloride
  7. dry with materialThe combined methylene chloride organic phases were dried
  8. concentrationconcentrated in vacuo
  9. additionThe fractions containing the product
  10. concentrationwere concentrated in vacuo
  11. custom1 mbar, 120° C.

Sources & evidence

ORD record
ord-f38a58d625a643eb90dd2f6e4ababfe5
Source dataset
uspto-grants-2002_05
Patent number
US06395748B2

Reaction notes

Loading…