Dexibuprofen → Ibuprofen, (+-)-

HRID 1729465Notes

Reaction equation

HRID 1729465 reaction equation
[CH3:1][C@H:2]([C:13]([OH:15])=[O:14])[C:3]1[CH:8]=[CH:7][C:6]([CH2:9][CH:10]([CH3:12])[CH3:11])=[CH:5][CH:4]=1>CCCCCCC>[OH:15][C:13]([CH:2]([C:3]1[CH:4]=[CH:5][C:6]([CH2:9][CH:10]([CH3:11])[CH3:12])=[CH:7][CH:8]=1)[CH3:1])=[O:14]

Participants

3

Reactant 1

HCID 39912Dexibuprofen

Product 1

HCID 3672Ibuprofen, (+-)-Yield 361.2%

Reagents, catalysts & solvents 1

HCID 8900HeptaneSolvent2×

Conditions

Temperature
220 °C

Procedure

Heptane is removed as stream 18, FIG. 1, by distillation in an evaporator at atmospheric pressure from a mixture [stream 15, FIG. 1]containing S(+)-ibuprofen (0.1912 moles, 39.43 g), R(-)-ibuprofen (0.5136 moles, 105.95 g), and heptane (ca. 390 g). During the distillation, water [30 g, stream 17]is injected into the base of the evaporator to help strip out the last traces of heptane and to minimize formation of ibuprofen ethyl ester. The molten evaporation residue [stream 33], which contains ibuprofen with an S/R ratio of 27/73, is first racemized by being heated under nitrogen at 220° C. for four hours and is then distilled at about 220° C., 10 mm HgA in an evaporator to provide a distillate [stream 19] of substantially pure racemized ibuprofen (0.6907 moles, 142.48 g, S/R ratio of 47:53) and an undistilled residue [stream 20, 2.91 g] for incineration as a waste stream. Racemized ibuprofen distillate [stream 19] is recycled to the first crop crystallization of crude S(+)-ibuprofen lysinate.

Workup

  1. distillationDuring the distillation, water [30 g, stream 17]is
  2. custominjected into the base of the evaporator
  3. customThe molten evaporation residue [stream 33], which
  4. distillationis then distilled at about 220° C.
  5. custom10 mm HgA in an evaporator

Sources & evidence

ORD record
ord-17792680a0df4a2baa88412409e070c8
Source dataset
uspto-grants-1994_07
Patent number
US05332834

Reaction notes

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