Carbon Dioxide → Clobuzarit

HRID 1702541Notes

Reaction equation

HRID 1702541 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:13]=[CH:12][C:11]([CH:14]3[O:18][C:17](=[O:19])[C:16]([CH3:21])([CH3:20])[O:15]3)=[CH:10][CH:9]=2)=[CH:4][CH:3]=1.C(=O)=O.[BH4-].[Na+].[OH-].[Na+]>[Pd].C(O)C.O>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]([C:8]2[CH:13]=[CH:12][C:11]([CH2:14][O:15][C:16]([CH3:21])([CH3:20])[C:17]([OH:19])=[O:18])=[CH:10][CH:9]=2)=[CH:6][CH:7]=1

Participants

8

Reactant 4

HCID 280Carbon DioxideHCID 14798Sodium HydroxideHCID 4311764Sodium borohydrideHCID 127737612-[4-(4-Chlorophenyl)phenyl]-5,5-dimethyl-1,3-dioxolan-4-one

Product 1

HCID 71697ClobuzaritYield 42%

Reagents, catalysts & solvents 3

HCID 23938PalladiumCatalystHCID 702EthanolSolvent2×HCID 962WaterSolvent2×

Procedure

A stirred suspension of 2-[4-(4-chlorophenyl)phenyl]-5,5-dimethyl-1,3-dioxolan-4-one (100.0 g.), 5% w/w palladium on carbon (10 g.) in a mixture of ethanol (500 ml.) and water (1000 ml.) was cooled to 10° to 15° C. and treated with carbon dioxide gas. The temperature and gas flow were maintained during the addition of a solution of sodium borohydride (63.0 g.) in water (250 ml.) during 1 hour. After 5 hours at 15° to 20° C. the pH of the reaction mixture was adjusted to pH 12 with 47% w/w sodium hydroxide solution and diluted with ethanol (1000 ml.). The residue was separated by filtration and washed successively with ethanol (2×250 ml.) and water (2×250 ml.). The combined filtrate and washings were evaporated to about half volume and the pH adjusted to 3 with 34% w/w hydrochloric acid. The solid which formed was recrystallised twice from toluene to give 2-[4-(4-chlorophenyl)benzyloxy]-2-methylpropionic acid, (m.p. 154°-155° C.) in 42% yield.

Workup

  1. temperaturewas cooled to 10° to 15° C.
  2. customThe residue was separated by filtration
  3. washwashed successively with ethanol (2×250 ml.) and water (2×250 ml.)
  4. customThe combined filtrate and washings were evaporated to about half volume
  5. customThe solid which formed
  6. customwas recrystallised twice from toluene

Sources & evidence

ORD record
ord-273fdca7753e432eb6368eca02bdfd13
Source dataset
uspto-grants-1982_09
Patent number
US04348322

Reaction notes

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