2-(4-Nitrophenyl)propionic acid → (R)-2-(4-Nitrophenyl)propanoic acid

HRID 392926

Reaction equation

HRID 392926 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([CH:10]([CH3:14])[C:11]([OH:13])=[O:12])=[CH:6][CH:5]=1)([O-:3])=[O:2]>C(OCC)(=O)C>[N+:1]([C:4]1[CH:5]=[CH:6][C:7]([C@@H:10]([CH3:14])[C:11]([OH:13])=[O:12])=[CH:8][CH:9]=1)([O-:3])=[O:2]

Participants

3

Reactant 1

HCID 892442-(4-Nitrophenyl)propionic acid

Product 1

HCID 1485472(R)-2-(4-Nitrophenyl)propanoic acid

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent2×

Procedure

A 2 liter three necked flask equipped with a mechanical stirrer is charged with racemic 2-(4-nitrophenyl)propionic acid (40.55 grams, 0.208 mol) and ethyl acetate (1600.0 mL). To this solution at 30° C. was then added S(−)-α-methylbenzylamine (13.49 mL, 0.104 mol) all at once. Reaction exothermed to 38° C. with massive formation of a white precipitate in less than 15.0 minutes. The reaction mixture was then heated at ethyl acetate reflux for 10.0 minutes and allowed to equilibrate to room temperature with stirring overnight. The precipitate was then filtered to give a semi-dried white product, (2R)-2-(4-nitrophenyl)propanoic acid, S(−)-α-methylbenzylamine (wet cake=25.43 grams). Reslurried the wet cake in ethyl acetate (1600.0 mL) at reflux for 10.0 minutes, stirred to room temperature overnight, and filtered the white precipitate, (2R)-2-(4-nitrophenyl)propanoic acid, S(−)-α-methylbenzylamine, (wet cake=21.02 grams, ee=91.4%). Repeated the later again and dried the precipitate at 40° C. in a vacuum oven for 24.0 hours, (2R)-2-(4-nitrophenyl)propanoic acid, S(−)-α-methylbenzylamine, (18.02 g, 55%, ee=95%); 1H nmr (DMSO, 300 MHz) δ 1.31-1.32 (d, 3H), 1.37-1.38 (d, 3H), 3.56-3.60 (m, 1H), 4.18-4.20 (m, 1H), 7.27-7.53 (aromatic, 7H), 8.09-8.12 (aromatic, 2H);

Workup

  1. customat 30° C.
  2. customReaction
  3. waitexothermed to 38° C. with massive formation of a white precipitate in less than 15.0 minutes
  4. temperaturereflux for 10.0 minutes
  5. customto equilibrate to room temperature
  6. filtrationThe precipitate was then filtered

Sources & evidence

ORD record
ord-a1970d239e7e47bda6108ede950d0f7d
Source dataset
uspto-grants-2004_10
Patent number
US06803484B2

Linked notes

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