Methanol → cyclohexyl(hydroxy)acetic acid

HRID 2105761Notes

Reaction equation

HRID 2105761 reaction equation
CO.[C:3]([OH:13])(=[O:12])[CH:4]([C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)[OH:5]>[Rh].C(O)(=O)C>[CH:6]1([CH:4]([OH:5])[C:3]([OH:13])=[O:12])[CH2:11][CH2:10][CH2:9][CH2:8][CH2:7]1

Participants

5

Reactant 2

HCID 887MethanolHCID 1292Mandelic Acid

Product 1

HCID 271989cyclohexyl(hydroxy)acetic acidYield 80.5%

Reagents, catalysts & solvents 2

HCID 23948RhodiumCatalystHCID 176Acetic AcidSolvent

Procedure

To a solution of 200 mL methanol were added 38.0 g mandelic acid, 2.5 mL acetic acid, and 7.5 g rhodium on carbon (5%, Engelhard 5864). The mixture was sealed in an autoclave, purged with nitrogen, and then filled with hydrogen gas. Hydrogenation was carried out at room temperature for 8 hours at 1400 psi hydrogen. The reaction mixture was then removed from the autoclave and filtered. The filtrate was concentrated and recrystallized from toluene. The colorless crystals were collected by filtration and dried under vacuum to give 31.8 g (80.5%) of racemic 2-cyclohexyl-2-hydroxyacetic acid. 1H NMR (DMSO-d6): δ (ppm) 3.71 (d, 1H), 1.66-1.55 (m, 6H), 1.16-1.09 (m, 5H). 13C NMR (DMSO-d6): δ (ppm) 175.27, 74.19, 41.15, 28.86, 26.74, 25.84, 25.76, 25.57. IR (KBr): ν (cm−1) 3440, 2933, 2856, 1718, 1450, 1280, 1255, 1230, 1103. Anal. Calcd. for C8H14O3: C, 60.74; H, 8.92. Found: C, 61.12; H, 9.28. mp 135-136° C.

Workup

  1. customThe mixture was sealed in an autoclave
  2. custompurged with nitrogen
  3. additionfilled with hydrogen gas
  4. customThe reaction mixture was then removed from the autoclave
  5. filtrationfiltered
  6. concentrationThe filtrate was concentrated
  7. customrecrystallized from toluene
  8. filtrationThe colorless crystals were collected by filtration
  9. customdried under vacuum

Sources & evidence

ORD record
ord-dd55a14fe415469c93bbc508f0dd3b95
Source dataset
uspto-grants-2009_08
Patent number
US07579429B2

Reaction notes

Loading…