Pyridine → Benzoic Acid

HRID 2414186Notes

Reaction equation

HRID 2414186 reaction equation
C(=[O:5])C(C)C.[C:6](N)(=[O:13])[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1.C(NC=C(C)C)(=O)C1C=CC=CC=1.[CH3:28][C@H:29]1[CH2:34][C@@H:33]([OH:35])[C@H:32]([CH:36]([CH3:38])[CH3:37])[CH2:31][CH2:30]1.N1C=CC=CC=1>C1COCC1>[C:6]([OH:13])(=[O:5])[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1.[CH3:28][C@H:29]1[CH2:34][C@@H:33]([OH:35])[C@H:32]([CH:36]([CH3:38])[CH3:37])[CH2:31][CH2:30]1

Participants

8

Reactant 5

HCID 1049PyridineHCID 2331BenzamideHCID 6561IsobutyraldehydeHCID 16666(-)-MentholHCID 12435423N-(2-Methylprop-1-en-1-yl)benzamide2×

Product 2

HCID 243Benzoic AcidHCID 16666(-)-Menthol

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
250 °C

Procedure

0.10 mol of isobutyraldehyde and 0.20 mol of benzamide are heated together at 100° C. with stirring, and the product solid is heated in a sublimator at 250° C. and 1 mm Hg until formation of the enamide 1-benzoylamino-2-methylpropene is complete. A 70 mL stainless steel high pressure reactor fitted with a Pyrex glass liner and magnetic stir bar is charged with THF (5 mL), L-menthol (0.5 mmol), Co2 (CO)8 (0.05 mmol), pyridine (0.25 mmol), and 1-benzoylamino-2-methylpropene (0.5 mmol). The reactor is sealed, pressurized to 1500 psig with 15:1 CO:H2 and stirred for 24 hours at 100° C. The product mixture, isolated after removal of gas from the reactor vessel, contains a mixture of two diastereomeric valine derivatives, N-benzoyl-L-valine L-menthyl ester and N-benzoyl-D-valine L-menthyl ester. These diastereomers are separated by column chromatography on silica gel with benzene-ethyl acetate eluent and are separately hydrolyzed by heating to 100° C. in 1N HCl for 2 hours to give pure L- and D-valine, benzoic acid, and L-menthol, which is thereafter recycled to a repeat of the foregoing hydrocarboxylation reaction.

Workup

  1. customA 70 mL stainless steel high pressure reactor fitted with a Pyrex glass liner and magnetic stir bar
  2. customThe reactor is sealed
  3. stirringH2 and stirred for 24 hours at 100° C
  4. customThe product mixture, isolated
  5. customafter removal of gas from the reactor vessel
  6. additiona mixture of two diastereomeric valine
  7. customThese diastereomers are separated by column chromatography on silica gel with benzene-ethyl acetate eluent
  8. temperatureby heating to 100° C. in 1N HCl for 2 hours

Sources & evidence

ORD record
ord-d67afbcd44464439929bb70aeae17fdd
Source dataset
uspto-grants-1988_01
Patent number
US04721803

Reaction notes

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