Oxygen → HCID 854133, compound

HRID 1416090Notes

Reaction equation

HRID 1416090 reaction equation
O=O.[Cl:3][C:4]1[CH:9]=[CH:8][C:7]([C:10](=[C:14]([CH3:16])[CH3:15])[C:11]([OH:13])=[O:12])=[CH:6][CH:5]=1>CO.[Ru]>[Cl:3][C:4]1[CH:5]=[CH:6][C:7]([C@@H:10]([CH:14]([CH3:16])[CH3:15])[C:11]([OH:13])=[O:12])=[CH:8][CH:9]=1

Participants

5

Reactant 2

HCID 977OxygenHCID 139522262-(p-Chlorophenyl)-3-methylcrotonic acid

Product 1

HCID 854133HCID 854133, compoundYield 92%

Reagents, catalysts & solvents 2

HCID 23950RutheniumCatalystHCID 887MethanolSolvent2×

Procedure

Ruthenium-catalyzed hydrogenation. -- A catalyst solution was prepared in a glove box (O2 content <1 ppm) by dissolving 0.0914 g (0.119 mmol) of Ru(OAc)2 [(S)-BIPHEMP] in 50 ml of methanol and stirring at 20° for 15 minutes. Then, 5.0 g (23.74 mmol) of 2-(p- chlorophenyl)-3-methylcrotonic acid and 23 ml of methanol were placed in a 185 ml autoclave and the catalyst solution prepared above was added. The autoclave was sealed and the hydrogenation was carried out at 20° while stirring and under a constant pressure of 60 bar. The conversion was 100% after 4 hours. The hydrogenation solution was evaporated at 50°/20 mbar and the residue was distilled in a bulb tube oven at 150°/0.2 mbar. There were obtained 4.6 g (92%) of (R)-2-(p-chlorophenyl)-3-methylbutyric acid as a colorless oil which crystallized out at RT; chemical purity 98.8 area %; 90.5% ee; [α]589 =-42.3° (c=1, methanol).

Workup

  1. customthe catalyst solution prepared
  2. additionabove was added
  3. customThe autoclave was sealed
  4. customwas carried out at 20°
  5. stirringwhile stirring and under a constant pressure of 60 bar
  6. customafter 4 hours
  7. customThe hydrogenation solution was evaporated at 50°/20 mbar
  8. distillationthe residue was distilled in a bulb tube oven at 150°/0.2 mbar

Sources & evidence

ORD record
ord-2f8e832ede444202a8b42e6cfe577ccb
Source dataset
uspto-grants-1999_06
Patent number
US05910606

Reaction notes

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