Sulfuric Acid → 2-Benzoylcyclohexanone

HRID 2188359Notes

Reaction equation

HRID 2188359 reaction equation
COCC(O)C.[OH-].[Na+].[C:9](OC)(=[O:16])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1.[C:19]1(=[O:25])[CH2:24][CH2:23][CH2:22][CH2:21][CH2:20]1.S(=O)(=O)(O)O>>[C:9]([CH:20]1[CH2:21][CH2:22][CH2:23][CH2:24][C:19]1=[O:25])(=[O:16])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1

Participants

6

Reactant 5

HCID 1118Sulfuric AcidHCID 7150Methyl BenzoateHCID 79001-Methoxy-2-propanolHCID 7967CyclohexanoneHCID 14798Sodium Hydroxide

Product 1

HCID 2756272-BenzoylcyclohexanoneYield 65%

Procedure

1-Methoxy-2-propanol (61.3 g; 0.68 mol), sodium hydroxide (16.0 g; 0.40 mol), and xylenes (300 mL) were placed into a four-necked, round bottom, half-liter flask equipped with a stirrer, a thermometer, and an Oldershaw column with a Dean-Stark trap and a condenser. The mixture was heated to boiling with stirring under a blanket of nitrogen and the water was azeotroped out (temperature of reflux 106-116° C.). When no more water was collected (23 mL of lower phase) some solvent was distilled off (215 mL), while xylenes (432.2 g, dry) were replaced, until no more alcohol was detected in the distillate (temperature of reflux 137° C.). The mixture in the flask was cooled down to and kept at 80° C. and the fractionation column and trap were replaced with a reflux condenser while maintaining the nitrogen stream. Methyl benzoate (68.1 g; 0.50 mol) was added, and slow addition over a period of 10 minutes of cyclohexanone (24.5 g, 0.250 mol) by means of a syringe pump was begun. After 19 minutes from the beginning of the addition of the ketone, the mixture was cooled down (an ice bath was used), and acidified by slow addition of 98% sulfuric acid (slightly over 24.5 g) with stirring. The mixture was transferred to a 1 L separatory funnel, washed with aqueous sodium bicarbonate, and then with water. Evaporation of the organic layer under vacuum and recrystallization from heptane afforded 32.86 g of BCH (65% yield based on cyclohexanone), with a purity of 99% (GC).

Workup

  1. customequipped with a stirrer
  2. temperatureThe mixture was heated
  3. customthe water was azeotroped out (temperature of reflux 106-116° C.)
  4. customWhen no more water was collected (23 mL of lower phase) some solvent
  5. distillationwas distilled off (215 mL)
  6. customwas detected in the distillate (temperature of reflux 137° C.)
  7. temperatureThe mixture in the flask was cooled down to and
  8. customkept at 80° C.
  9. customthe fractionation column and trap were replaced with a reflux condenser
  10. temperaturewhile maintaining the nitrogen stream
  11. temperaturethe mixture was cooled down (an ice bath was used)
  12. stirringwith stirring
  13. customThe mixture was transferred to a 1 L separatory funnel
  14. washwashed with aqueous sodium bicarbonate
  15. customEvaporation of the organic layer
  16. customunder vacuum and recrystallization from heptane
  17. customafforded 32.86 g of BCH (65% yield based on cyclohexanone)

Sources & evidence

ORD record
ord-97941871abdd48d79f24afa36ed2ccd5
Source dataset
uspto-grants-2002_06
Patent number
US06410795B1

Reaction notes

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